Acoustically resistive supported membrane assemblies

ABSTRACT

Water impermeable, air permeable membrane assemblies are described herein. In some embodiments, the assemblies include a polymer membrane and at least one support layer. Certain assemblies are configured to provide an acoustic impedance having phase angle of +45 degrees to −45 over a frequency range of 50 to 20,000 Hz.

FIELD

The field of the present disclosure relates to acoustic membraneassemblies.

BACKGROUND

Acoustic membrane assemblies can allow sound to propagate through andpast a membrane and to and from a device. Acoustic membranes can alsoprevent ingress of water, dust and other contaminants. There is anongoing need in the art for improved acoustic membranes.

SUMMARY

Covered embodiments are defined by the claims, not this summary. Thissummary is a high-level overview of various aspects and introduces someof the concepts that are further described in the Detailed Descriptionsection below. This summary is not intended to identify key or essentialfeatures of the claimed subject matter, nor is it intended to be used inisolation to determine the scope of the claimed subject matter. Thesubject matter should be understood by reference to appropriate portionsof the entire specification, any or all drawings, and each claim.

The present disclosure relates to an assembly comprising a polymermembrane and at least one support layer that includes a plurality ofopenings.

In some embodiments, the assembly comprises: a polymer membrane havingan air flow resistance ranging from 75 to 50,000 Rayls; and at least onesupport layer; at least a portion of the at least one support layer isin contact with the polymer membrane, the at least one support layer hasan airflow resistance of from 10 to 5000 Rayls; the assembly has aneffective stiffness that ranges from 0.0002 Pa/nm to 3,000 Pa/nm whenmeasured using the Vibrational Displacement Test (“VDT”); and theassembly has an acoustic impedance with a phase angle of +45 degrees to−45 degrees over a frequency range of 50 to 20,000 Hz as measured by theImpedance Tube Transfer Matrix Test (“ITTMT”).

In some embodiments, the assembly comprises: a polymer membrane havingan air flow resistance ranging from 75 Rayls to 50,000 Rayls; at leastone support layer; at least a portion of the at least one support layeris in contact with the at least one polymer membrane, the at least onesupport layer has an airflow resistance ranging from 10 Rayls to 5000Rayls; and the at least one support layer has an effective stiffnessthat: ranges from 0.05 Pa/nm to 25 Pa/nm measured using the VibrationalDisplacement Test (“VDT”); and the assembly has an acoustic impedancewith a phase angle of +45 degrees to −45 degrees over a frequency rangeof 50 to 20,000 Hz as measured by the Impedance Tube Transfer MatrixTest (“ITTMT”).

In some embodiments, the assembly comprises an airflow resistance offrom 100 to 50,000 Rayls; an effective stiffness from 0.0002 Pa/nm to3,000 Pa/nm when measured using the Vibrational Displacement Test(“VDT”); and an acoustic impedance with a phase angle of +45 degrees to−45 degrees over a frequency range of 50 to 20,000 Hz as measured by theImpedance Tube Transfer Matrix Test (“ITTMT”).

In some embodiments, the assembly has a water entry pressure rangingfrom 10 psi to 350 psi (“WEP”) measured in accordance with the CapillaryPiston Test (“CPT”).

In some embodiments, the assembly exhibits a transmission loss of from 3dB to 48 dB when measured by the Impedance Tube Transfer Matrix Test(“ITTMT”) over the frequency range of 50 to 20,000 Hz.

In some embodiments, the assembly comprises an airflow resistance offrom 100 to 50,000 Rayls; an effective stiffness from 0.0002 Pa/nm to3,000 Pa/nm when measured using the Vibrational Displacement Test(“VDT”); and a transmission loss that does not vary by more than 1.5dB/octave over the frequency range of 50 to 20,000 Hz when measured bythe Impedance Tube Transfer Matrix Test (“ITTMT”).

In some embodiments, the polymer membrane has a thickness ranging from0.025 microns to 300 microns.

In some embodiments, the polymer membrane comprises a plurality of poreswith different pore sizes.

In some embodiments, the plurality of pores has a maximum pore sizeranging from 0.1 to 30 microns.

In some embodiments, the polymer membrane has a bubble point rangingfrom 0.4 psi to 120 psi.

In some embodiments, the at least one support layer comprises aplurality of openings.

In some embodiments, the largest dimension of a single opening of theplurality of openings is 1 to 500 microns.

In some embodiments, the at least one support layer has a thickness of10 to 1000 microns

In some embodiments, the at least one support layer has an effectiveopen area of from 5% to 98%.

In some embodiments, the polymer membrane comprises expandedpolytetrafluoroethylene (ePTFE).

In some embodiments, the polymer membrane has a Young's Modulus rangingfrom 1 MPa to 1000 MPa.

In some embodiments, the assembly comprises a single support layer.

In some embodiments, the assembly comprises at least two support layers.

In some embodiments, the assembly comprises a first support layer and asecond support layer, and the polymer membrane is sandwiched between thefirst support layer the second support layer.

In some embodiments, the first and second support layers comprise thesame material.

In some embodiments, the first and second support layers comprise adifferent material.

In some embodiments, there is an adhesive between the polymer membraneand the at least one support layer.

In some embodiments, the at least one support layer comprisesfiberglass.

In some embodiments, the at least one support layer comprises a metal.

In some embodiments, the metal is brass.

In some embodiments, the one or more support layers comprises a mesh.

In some embodiments, the mesh is woven polyethylene terephthalate (PET)mesh.

In some embodiments, the mesh is extruded plastic non-woven mesh.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments of the disclosure are herein described, by way ofexample only, with reference to the accompanying drawings. With specificreference now to the drawings in detail, the embodiments shown are byway of example and for purposes of illustrative discussion ofembodiments of the disclosure. In this regard, the description takenwith the drawings makes apparent to those skilled in the art howembodiments of the disclosure may be practiced.

FIG. 1 depicts an exemplary assembly in accordance with the presentdisclosure and having a single support layer.

FIG. 2 depicts an additional exemplary assembly in accordance with thepresent disclosure having two support layers.

FIG. 3 is a schematic illustration of an exemplary 4-microphoneimpedance tube used for transmission loss and phase testing, asdescribed in Test Procedures section.

FIG. 4 depicts exemplary plates used for transmission loss testing withcompression, as described in Test Procedures section.

FIGS. 5 and 6 depict micrographs used to measure the % contact ofexemplary assemblies.

FIGS. 7-18 depict exemplary acoustic characteristics of exemplaryassemblies.

FIGS. 19-29 depict exemplary acoustic characteristics of exemplaryassemblies before and after air pressure test.

FIG. 30 depicts exemplary acoustic characteristics of exemplaryassemblies under compression force.

FIGS. 31-32 depict non-limiting examples of consistency of acousticcharacteristics of exemplary assemblies.

FIG. 33 depicts exemplary tunable acoustic characteristics ofnon-limiting assemblies.

DETAILED DESCRIPTION

Among those benefits and improvements that have been disclosed, otherobjects and advantages of this disclosure will become apparent from thefollowing description taken in conjunction with the accompanyingfigures. Detailed embodiments of the present disclosure are disclosedherein; however, the disclosed embodiments are merely illustrative ofthe disclosure that may be embodied in various forms. In addition, eachof the examples given regarding the various embodiments of thedisclosure are intended to be illustrative, and not restrictive.

Throughout the specification and claims, the following terms take themeanings explicitly associated herein, unless the context clearlydictates otherwise. The phrases “in one embodiment,” “in an embodiment,”and “in some embodiments” as used herein do not necessarily refer to thesame embodiment(s), though it may. Furthermore, the phrases “in anotherembodiment” and “in some other embodiments” as used herein do notnecessarily refer to a different embodiment, although it may. Allembodiments of the disclosure are intended to be combinable withoutdeparting from the scope or spirit of the disclosure.

As used herein, the term “based on” is not exclusive and allows forbeing based on additional factors not described, unless the contextclearly dictates otherwise. In addition, throughout the specification,the meaning of “a,” “an,” and “the” include plural references. Themeaning of “in” includes “in” and “on.”

All prior patents, publications, and test methods referenced herein areincorporated by reference in their entireties.

Some embodiments of the present disclosure are directed to apredominantly resistive supported acoustic membrane assembly thatcomprises a polymer membrane and at least one support layer.

In some embodiments, the polymer membrane in the assembly includes aplurality of pores. In some embodiments, the plurality of pores can havea maximum pore size. As used herein, “maximum pore size,” is the size ofthe largest pore of the plurality of pores.

In some embodiments, the plurality of pores can have a maximum pore sizeof 0.1 to 30 microns. In some embodiments, the plurality of pores canhave a maximum pore size of 0.3 to 30 microns. In some embodiments, theplurality of pores can have a maximum pore size of 0.5 to 30 microns. Insome embodiments, the plurality of pores can have a maximum pore size of10 to 30 microns. In some embodiments, the plurality of pores can have amaximum pore size of 20 to 30 microns. In some embodiments, theplurality of pores can have a maximum pore size of 25 to 30 microns.

In some embodiments, the plurality of pores can have a maximum pore sizeof 0.2 to 8 microns. In some embodiments, the plurality of pores canhave a maximum pore size of 0.4 to 4 microns. In some embodiments, theplurality of pores can have a maximum pore size of 0.8 to 2 microns. Insome embodiments, the plurality of pores can have a maximum pore size of1 to 1.6 microns.

In some embodiments, the plurality of pores can have a maximum pore sizeof 0.2 to 4 microns. In some embodiments, the plurality of pores canhave a maximum pore size of 0.2 to 2 microns. In some embodiments, theplurality of pores can have a maximum pore size of 0.2 to 1.6 microns.In some embodiments, the plurality of pores can have a maximum pore sizeof 0.2 to 1 microns. In some embodiments, the plurality of pores canhave a maximum pore size of 0.2 to 0.8 microns. In some embodiments, theplurality of pores can have a maximum pore size of 0.2 to 0.4 microns.

In some embodiments, the plurality of pores can have a maximum pore sizeof 0.4 to 8 microns. In some embodiments, the plurality of pores canhave a maximum pore size of 0.8 to 8 microns. In some embodiments, theplurality of pores can have a maximum pore size of 1 to 8 microns. Insome embodiments, the plurality of pores can have a maximum pore size of1.6 to 8 microns. In some embodiments, the plurality of pores can have amaximum pore size of 2 to 8 microns. In some embodiments, the pluralityof pores can have a maximum pore size of 4 to 8 microns.

In some embodiments, the polymer membrane has a thickness ranging from0.06 microns to 130 microns. In some embodiments, the polymer membranehas a thickness ranging from 0.12 microns to 65 microns. In someembodiments, the polymer membrane has a thickness ranging from 0.24microns to 30 microns. In some embodiments, the polymer membrane has athickness ranging from 0.5 microns to 15 microns. In some embodiments,the polymer membrane has a thickness ranging from 1 micron to 8 microns.In some embodiments, the polymer membrane has a thickness ranging from 2microns to 4 microns.

In some embodiments, the polymer membrane has a thickness ranging from0.025 microns to 300 microns. In some embodiments, the polymer membranehas a thickness ranging from 0.061 microns to 126 microns. In someembodiments, the polymer membrane has a thickness ranging from 0.025microns to 150 microns.

In some embodiments, the polymer membrane has a thickness ranging from0.025 microns to 150 microns. In some embodiments, the polymer membranehas a thickness ranging from 0.025 microns to 100 microns. In someembodiments, the polymer membrane has a thickness ranging from 0.025microns to 50 microns. In some embodiments, the polymer membrane has athickness ranging from 0.025 microns to 25 microns. In some embodiments,the polymer membrane has a thickness ranging from 0.025 microns to 10microns. In some embodiments, the polymer membrane has a thicknessranging from 0.025 microns to 5 microns. In some embodiments, thepolymer membrane has a thickness ranging from 0.025 microns to 2.5microns. In some embodiments, the polymer membrane has a thicknessranging from 0.025 microns to 1 microns. In some embodiments, thepolymer membrane has a thickness ranging from 0.025 microns to 0.3microns.

In some embodiments, the polymer membrane has a thickness ranging from0.06 microns to 65 microns. In some embodiments, the polymer membranehas a thickness ranging from 0.06 microns to 30 microns. In someembodiments, the polymer membrane has a thickness ranging from 0.06microns to 15 microns. In some embodiments, the polymer membrane has athickness ranging from 0.06 microns to 8 microns. In some embodiments,the polymer membrane has a thickness ranging from 0.06 micron to 4microns. In some embodiments, the polymer membrane has a thicknessranging from 0.06 microns to 2 microns. In some embodiments, the polymermembrane has a thickness ranging from 0.06 microns to 1 micron. In someembodiments, the polymer membrane has a thickness ranging from 0.06microns to 0.5 microns. In some embodiments, the polymer membrane has athickness ranging from 0.06 microns to 0.24 microns. In someembodiments, the polymer membrane has a thickness ranging from 0.06microns to 0.12 microns.

In some embodiments, the polymer membrane has a thickness ranging from0.12 microns to 130 microns. In some embodiments, the polymer membranehas a thickness ranging from 0.24 microns to 130 microns. In someembodiments, the polymer membrane has a thickness ranging from 0.5microns to 130 microns. In some embodiments, the polymer membrane has athickness ranging from 1 micron to 130 microns. In some embodiments, thepolymer membrane has a thickness ranging from 2 microns to 130 microns.In some embodiments, the polymer membrane has a thickness ranging from 4microns to 130 microns. In some embodiments, the polymer membrane has athickness ranging from 8 microns to 130 microns. In some embodiments,the polymer membrane has a thickness ranging from 15 microns to 130microns. In some embodiments, the polymer membrane has a thicknessranging from 30 microns to 130 microns. In some embodiments, the polymermembrane has a thickness ranging from 65 microns to 130 microns.

In some embodiments, the polymer membrane comprises at least one of:polyolefins, polyurethanes, polyesters, polyamides, polyketones,polysulfones, or polycarbonates. In some embodiments, the polymermembrane can comprise a fluoropolymer. In some embodiments, thefluoropolymer comprises one or more of PVDF, polyvinylidene diflouride,poly(tetrafluoroethylene-co-hexafluoropropylene (FEP),poly(ethylene-alt-tetrafluoroethylene) (ETFE),polychlorotrifluoroethylene (PCTFE),poly(tetrafluoroethylene-co-perfluoropropyl vinyl ether) (PFA),poly(vinylidene fluoride-co-hexafluoropropylene (PVDF-co-HFP), polyvinylfluoride (PVF), or any combination thereof.

In some embodiments, the fluoropolymer is polytetrafluoroethylene(PTFE). In some embodiments, the PTFE is expandedpolytetrafluoroethylene (ePTFE). In some embodiments, the ePTFEcomprises the same microstructure, characterized by nodes interconnectedby fibrils, as one of the ePTFE compositions disclosed in U.S. Pat. No.3,953,566 to Gore or U.S. Pat. No. 4,902,423 to Bacino.

In a non-limiting example, the polymer is a lightweight ePTFE membranehaving high intrinsic strength, prepared according to the generalmethodology described in U.S. Pat. No. 3,953,566 to Gore. Thenon-limiting example polymer membrane can be a biaxially orientedmembrane that is highly crystalline (i.e., having a crystallinity indexof at least 94%) and has a matrix tensile strength in both thelongitudinal and transverse directions of at least 600 MPa. Thenon-limiting example polymer membrane may be comprised of a plurality ofstacked ePTFE layers, where each layer has a mass per area of less than0.1 g/m².

In some embodiments, the polymer membrane has an air flow resistanceranging from 75 to 50,000 Rayls. In some embodiments, the polymermembrane has an air flow resistance ranging from 100 to 50,000 Rayls. Insome embodiments, the polymer membrane has an air flow resistanceranging from 200 to 25,000 Rayls. In some embodiments, the polymermembrane has an air flow resistance ranging from 800 to 12,500 Rayls. Insome embodiments, the polymer membrane has an air flow resistanceranging from 1600 to 6000 Rayls. In some embodiments, the polymermembrane has an air flow resistance ranging from 3000 to 4000 Rayls.

In some embodiments, the polymer membrane has an air flow resistanceranging from 200 to 25,000 Rayls. In some embodiments, the polymermembrane has an air flow resistance ranging from 200 to 12,500 Rayls. Insome embodiments, the polymer membrane has an air flow resistanceranging from 200 to 6000 Rayls. In some embodiments, the polymermembrane has an air flow resistance ranging from 200 to 4000 Rayls. Insome embodiments, the polymer membrane has an air flow resistanceranging from 200 to 3000 Rayls. In some embodiments, the polymermembrane has an air flow resistance ranging from 200 to 1600 Rayls. Insome embodiments, the polymer membrane has an air flow resistanceranging from 200 to 800 Rayls. In some embodiments, the polymer membranehas an air flow resistance ranging from 400 to 800 Rayls.

In some embodiments, the polymer membrane has an air flow resistanceranging from 400 to 50,000 Rayls. In some embodiments, the polymermembrane has an air flow resistance ranging from 800 to 50,000 Rayls. Insome embodiments, the polymer membrane has an air flow resistanceranging from 1600 to 50,000 Rayls. In some embodiments, the polymermembrane has an air flow resistance ranging from 3000 to 50,000 Rayls.In some embodiments, the polymer membrane has an air flow resistanceranging from 6000 to 50,000 Rayls. In some embodiments, the polymermembrane has an air flow resistance ranging from 12,500 to 50,000 Rayls.In some embodiments, the polymer membrane has an air flow resistanceranging from 25,000 to 50,000 Rayls.

In some embodiments, the polymer membrane has a Young's Modulus rangingfrom 1 MPa to 1000 MPa. In some embodiments, the polymer membrane has aYoung's Modulus ranging from 2 MPa to 1000 MPa. In some embodiments, thepolymer membrane has a Young's Modulus ranging from 5 MPa to 1000 MPa.In some embodiments, the polymer membrane has a Young's Modulus rangingfrom 10 MPa to 1000 MPa. In some embodiments, the polymer membrane has aYoung's Modulus ranging from 25 MPa to 1000 MPa. In some embodiments,the polymer membrane has a Young's Modulus ranging from 50 MPa to 1000MPa. In some embodiments, the polymer membrane has a Young's Modulusranging from 100 MPa to 1000 MPa. In some embodiments, the polymermembrane has a Young's Modulus ranging from 250 MPa to 1000 MPa. In someembodiments, the polymer membrane has a Young's Modulus ranging from 500MPa to 1000 MPa. In some embodiments, the polymer membrane has a Young'sModulus ranging from 750 MPa to 1000 MPa.

In some embodiments, the polymer membrane has a Young's Modulus rangingfrom 4 MPa to 360 MPa. In some embodiments, the polymer membrane has aYoung's Modulus ranging from 8 MPa to 180 MPa. In some embodiments, thepolymer membrane has a Young's Modulus ranging from 16 MPa to 90 MPa. Insome embodiments, the polymer membrane has a Young's Modulus rangingfrom 32 MPa to 45 MPa.

In some embodiments, the polymer membrane has a Young's Modulus rangingfrom 4 MPa to 360 MPa. In some embodiments, the polymer membrane has aYoung's Modulus ranging from 4 MPa to 180 MPa. In some embodiments, thepolymer membrane has a Young's Modulus ranging from 4 MPa to 90 MPa. Insome embodiments, the polymer membrane has a Young's Modulus rangingfrom 4 MPa to 45 MPa. In some embodiments, the polymer membrane has aYoung's Modulus ranging from 4 MPa to 32 MPa. In some embodiments, thepolymer membrane has a Young's Modulus ranging from 4 MPa to 16 MPa. Insome embodiments, the polymer membrane has a Young's Modulus rangingfrom 4 MPa to 8 MPa.

In some embodiments, the polymer membrane has a Young's Modulus rangingfrom 8 MPa to 360 MPa. In some embodiments, the polymer membrane has aYoung's Modulus ranging from 16 MPa to 360 MPa. In some embodiments, thepolymer membrane has a Young's Modulus ranging from 32 MPa to 360 MPa.In some embodiments, the polymer membrane has a Young's Modulus rangingfrom 45 MPa to 360 MPa. In some embodiments, the polymer membrane has aYoung's Modulus ranging from 90 MPa to 360 MPa. In some embodiments, thepolymer membrane has a Young's Modulus ranging from 180 MPa to 360 MPa.

In some embodiments, the polymer membrane has a bubble point rangingfrom 0.4 to 120 psi. In some embodiments, the polymer membrane has abubble point ranging from 0.4 to 100 psi. In some embodiments, thepolymer membrane has a bubble point ranging from 0.4 to 80 psi. In someembodiments, the polymer membrane has a bubble point ranging from 0.4 to60 psi. In some embodiments, the polymer membrane has a bubble pointranging from 0.4 to 40 psi. In some embodiments, the polymer membranehas a bubble point ranging from 0.4 to 20 psi. In some embodiments, thepolymer membrane has a bubble point ranging from 0.4 to 10 psi. In someembodiments, the polymer membrane has a bubble point ranging from 0.4 to5 psi. In some embodiments, the polymer membrane has a bubble pointranging from 0.4 to 2 psi. In some embodiments, the polymer membrane hasa bubble point ranging from 0.4 to 1 psi. In some embodiments, thepolymer membrane has a bubble point ranging from 0.4 to 0.5 psi.

In some embodiments, the polymer membrane has a bubble point rangingfrom 1.5 to 56 psi. In some embodiments, the polymer membrane has abubble point ranging from 1.5 to 60 psi. In some embodiments, thepolymer membrane has a bubble point ranging from 3 to 28 psi. In someembodiments, the polymer membrane has a bubble point ranging from 6 to16 psi.

In some embodiments, the polymer membrane has a bubble point rangingfrom 1.5 to 28 psi. In some embodiments, the polymer membrane has abubble point ranging from 1.5 to 14 psi. In some embodiments, thepolymer membrane has a bubble point ranging from 1.5 to 7 psi. In someembodiments, the polymer membrane has a bubble point ranging from 1.5 to3.5 psi.

In some embodiments, the polymer membrane has a bubble point rangingfrom 3 to 56 psi. In some embodiments, the polymer membrane has a bubblepoint ranging from 3 to 28 psi. In some embodiments, the polymermembrane has a bubble point ranging from 3 to 14 psi. In someembodiments, the polymer membrane has a bubble point ranging from 3 to 7psi.

In some embodiments, the polymer membrane can have a homogeneous poresize distribution. A homogenous pore size distribution is where the poresize distribution remains the same as a function of thickness within themembrane. an inhomogeneous pore size distribution is where the pore sizedistribution changes as a function of thickness within the membrane. Insome embodiments, the pore size distribution is homogeneous. In otherembodiments, the pore size distribution is inhomogeneous.

In some embodiments, the polymer membrane has a mass per unit arearanging from 0.01 to 7.5 g/m². In some embodiments, the polymer membranehas a mass per unit area ranging from 0.05 to 5 g/m². In someembodiments, the polymer membrane has a mass per unit area ranging from0.1 to 2 g/m². In some embodiments, the polymer membrane has a mass perunit area ranging from 0.2 to 1 g/m². In some embodiments, the polymermembrane has a mass per unit area ranging from 0.4 to 1 g/m².

In some embodiments, the polymer membrane has a mass per unit arearanging from 0.01 to 5 g/m². In some embodiments, the polymer membranehas a mass per unit area ranging from 0.01 to 2 g/m². In someembodiments, the polymer membrane has a mass per unit area ranging from0.01 to 1 g/m². In some embodiments, the polymer membrane has a mass perunit area ranging from 0.01 to 0.5 g/m². In some embodiments, thepolymer membrane has a mass per unit area ranging from 0.01 to 0.4 g/m².In some embodiments, the polymer membrane has a mass per unit arearanging from 0.01 to 0.2 g/m². In some embodiments, the polymer membranehas a mass per unit area ranging from 0.01 to 0.05 g/m².

In some embodiments, the polymer membrane has a mass per unit arearanging from 0.05 to 7.5 g/m². In some embodiments, the polymer membranehas a mass per unit area ranging from 0.1 to 7.5 g/m². In someembodiments, the polymer membrane has a mass per unit area ranging from0.2 to 7.5 g/m². In some embodiments, the polymer membrane has a massper unit area ranging from 0.4 to 7.5 g/m². In some embodiments, thepolymer membrane has a mass per unit area ranging from 0.5 to 7.5 g/m².In some embodiments, the polymer membrane has a mass per unit arearanging from 1 to 7.5 g/m². In some embodiments, the polymer membranehas a mass per unit area ranging from 2 to 7.5 g/m². In someembodiments, the polymer membrane has a mass per unit area ranging from5 to 7.5 g/m².

In some embodiments, the polymer membrane exhibits a Water EntryPressure (“WEP”) of 0.5 to 450 psi. In some embodiments, the polymermembrane exhibits a WEP of 0.5 psi to 200 psi. In some embodiments, thepolymer membrane exhibits a WEP of 1 psi to 150 psi. In someembodiments, the polymer membrane exhibits a WEP of 1.0 psi to 100 psi.In some embodiments, the polymer membrane exhibits a WEP of 1 psi to 50psi. In some embodiments, the polymer membrane exhibits a WEP of 25 psito 150.0 psi. In some embodiments, the polymer membrane exhibits a WEPof 50.0 psi to 150.0 psi. In some embodiments, the polymer membraneexhibits a WEP of 1.0 psi to 110.8 psi.

In some embodiments, the polymer membrane exhibits a Water EntryPressure (“WEP”) of 1.4 to 432 psi. In some embodiments, the polymermembrane exhibits a Water Entry Pressure (“WEP”) of 0.95 to 432 psi. Insome embodiments, the polymer membrane exhibits a Water Entry Pressure(“WEP”) of 0.95 to 111 psi.

In some embodiments, at least a portion of the at least one supportlayer comprises a portion that is in contact with the polymer membrane.“Contact” includes but does not limit to direct physical contact andbond through adhesive, lamination and static. Contact is measured usingthe procedure defined herein in the Test Procedures section.

The % contact between the polymer membrane and support layer can bedetermined using the method described in the Test Procedures section. Insome embodiments, 0.1% to 99.6% of the at least one support layer is incontact with the polymer membrane. In some embodiments, 1% to 50% of theat least one support layer is in contact with the polymer membrane. Insome embodiments, 2% to 25% of the at least one support layer is incontact with the polymer membrane. In some embodiments, 4% to 12% of theat least one support layer is in contact with the polymer membrane.

In some embodiments, 0.5% to 80% of the at least one support layer is incontact with the polymer membrane. In some embodiments, 1% to 40% of theat least one support layer is in contact with the polymer membrane. Insome embodiments, 2% to 20% of the at least one support layer is incontact with the polymer membrane. In some embodiments, 5% to 10% of theat least one support layer is in contact with the polymer membrane.

In some embodiments, 12% to 91% of the at least one support layer is incontact with the polymer membrane. In some embodiments, 24% to 76% ofthe at least one support layer is in contact with the polymer membrane.In some embodiments, 36% to 48% of the at least one support layer is incontact with the polymer membrane.

The “% open area” is the portion of the at least one support layer thatdoes not contact the polymer membrane. In some embodiments, the % openarea of the at least one support layer ranges from 5% to 98%. In someembodiments, the % open area of the at least one support layer rangesfrom 10% to 49%. In some embodiments, the % open area of the at leastone support layer ranges from 20% to 24%. In some embodiments, the %open area of the at least one support layer ranges from 12% to 40%. Insome embodiments, the % open area of the at least one support layerranges from 24% to 80%.

In some embodiments, the largest dimension of a single opening of theplurality of openings of the at least one support layer ranges from 1 to500 microns. In some embodiments, the largest dimension of a singleopening of the plurality of openings of the at least one support layerranges from 5 to 500 microns. In some embodiments, the largest dimensionof a single opening of the plurality of openings of the at least onesupport layer ranges from 2 to 250 microns. In some embodiments, thelargest dimension of a single opening of the plurality of openings ofthe at least one support layer ranges from 4 to 125 microns. In someembodiments, the largest dimension of a single opening of the pluralityof openings of the at least one support layer ranges from 8 to 75microns. In some embodiments, the largest dimension of a single openingof the plurality of openings of the at least one support layer rangesfrom 16 to 50 microns. In some embodiments, the largest dimension of asingle opening of the plurality of openings of the at least one supportlayer ranges from 25 to 32 microns.

In some embodiments, the largest dimension of a single opening of theplurality of openings of the at least one support layer ranges from 10to 350 microns. In some embodiments, the largest dimension of a singleopening of the plurality of openings of the at least one support layerranges from 20 to 180 microns. In some embodiments, the largestdimension of a single opening of the plurality of openings of the atleast one support layer ranges from 40 to 90 microns.

In some embodiments, the largest dimension of a single opening of theplurality of openings of the at least one support layer ranges from 20to 40 microns. In some embodiments, the largest dimension of a singleopening of the plurality of openings of the at least one support layerranges from 20 to 80 microns. In some embodiments, the largest dimensionof a single opening of the plurality of openings of the at least onesupport layer ranges from 20 to 90 microns. In some embodiments, thelargest dimension of a single opening of the plurality of openings ofthe at least one support layer ranges from 20 to 180 microns.

In some embodiments, the largest dimension of a single opening of theplurality of openings of the at least one support layer ranges from 40to 350 microns. In some embodiments, the largest dimension of a singleopening of the plurality of openings of the at least one support layerranges from 80 to 350 microns. In some embodiments, the largestdimension of a single opening of the plurality of openings of the atleast one support layer ranges from 90 to 350 microns. In someembodiments, the largest dimension of a single opening of the pluralityof openings of the at least one support layer ranges from 180 to 350microns.

In some embodiments, the at least one support layer has a thickness of 1to 1000 microns. In some embodiments, the at least one support layer hasa thickness of 2 to 500 microns. In some embodiments, the at least onesupport layer has a thickness of 4 to 250 microns. In some embodiments,the at least one support layer has a thickness of 8 to 125 microns. Insome embodiments, the at least one support layer has a thickness of 16to 75 microns. In some embodiments, the at least one support layer has athickness of 32 to 50 microns.

In some embodiments, the at least one support layer has a thickness of10 to 1000 microns. In some embodiments, the at least one support layerhas a thickness of 30 to 600 microns. In some embodiments, the at leastone support layer has a thickness of 60 to 300 microns. In someembodiments, the at least one support layer has a thickness of 80 to 200microns. In some embodiments, the at least one support layer has athickness of 90 to 100 microns.

In some embodiments, the at least one support layer has a thickness of40 to 200 microns. In some embodiments, the at least one support layerhas a thickness of 40 to 300 microns. In some embodiments, the at leastone support layer has a thickness of 40 to 100 microns. In someembodiments, the at least one support layer has a thickness of 40 to 90microns. In some embodiments, the at least one support layer has athickness of 40 to 80 microns. In some embodiments, the at least onesupport layer has a thickness of 40 to 60 microns.

In some embodiments, the at least one support layer has a thickness of40 to 410 microns. In some embodiments, the at least one support layerhas a thickness of 60 to 410 microns. In some embodiments, the at leastone support layer has a thickness of 80 to 410 microns. In someembodiments, the at least one support layer has a thickness of 90 to 410microns. In some embodiments, the at least one support layer has athickness of 100 to 410 microns. In some embodiments, the at least onesupport layer has a thickness of 200 to 410 microns. In someembodiments, the at least one support layer has a thickness of 300 to410 microns. In some embodiments, the at least one support layer has athickness of 20 to 750 microns.

In some embodiments, the at least one support layer has an air flowresistance ranging from 10 to 5000 Rayls. In some embodiments, the atleast one support layer has an air flow resistance ranging from 20 to4000 Rayls. In some embodiments, the at least one support layer has anair flow resistance ranging from 20 to 3000 Rayls. In some embodiments,the at least one support layer has an air flow resistance ranging from40 to 3000 Rayls. In some embodiments, the at least one support layerhas an air flow resistance ranging from 80 to 2500 Rayls. In someembodiments, the at least one support layer has an air flow resistanceranging from 160 to 2000 Rayls. In some embodiments, the at least onesupport layer has an air flow resistance ranging from 300 to 1800 Rayls.In some embodiments, the at least one support layer has an air flowresistance ranging from 600 to 1600 Rayls. In some embodiments, the atleast one support layer has an air flow resistance ranging from 800 to1200 Rayls. In some embodiments, the at least one support layer has anair flow resistance ranging from 900 to 1000 Rayls.

In some embodiments, the at least one support layer has an air flowresistance ranging from 10 to 1500 Rayls. In some embodiments, the atleast one support layer has an air flow resistance ranging from 20 to750 Rayls. In some embodiments, the at least one support layer has anair flow resistance ranging from 40 to 400 Rayls. In some embodiments,the at least one support layer has an air flow resistance ranging from80 to 200 Rayls. In some embodiments, the at least one support layer hasan air flow resistance ranging from 90 to 100 Rayls.

In some embodiments, the at least one support layer has an air flowresistance ranging from 40 to 1500 Rayls. In some embodiments, the atleast one support layer has an air flow resistance ranging from 43 to1458 Rayls. In some embodiments, the at least one support layer has anair flow resistance ranging from 80 to 750 Rayls. In some embodiments,the at least one support layer has an air flow resistance ranging from160 to 500 Rayls. In some embodiments, the at least one support layerhas an air flow resistance ranging from 250 to 320 Rayls.

In some embodiments, the at least one support layer has an air flowresistance ranging from 40 to 750 Rayls. In some embodiments, the atleast one support layer has an air flow resistance ranging from 40 to500 Rayls. In some embodiments, the at least one support layer has anair flow resistance ranging from 40 to 320 Rayls. In some embodiments,the at least one support layer has an air flow resistance ranging from40 to 250 Rayls. In some embodiments, the at least one support layer hasan air flow resistance ranging from 40 to 160 Rayls. In someembodiments, the at least one support layer has an air flow resistanceranging from 40 to 80 Rayls.

In some embodiments, the at least one support layer has an air flowresistance ranging from 80 to 1500 Rayls. In some embodiments, the atleast one support layer has an air flow resistance ranging from 160 to1500 Rayls. In some embodiments, the at least one support layer has anair flow resistance ranging from 250 to 1500 Rayls. In some embodiments,the at least one support layer has an air flow resistance ranging from320 to 1500 Rayls. In some embodiments, the at least one support layerhas an air flow resistance ranging from 750 to 1500 Rayls.

As used herein, “effective stiffness” is defined as the ratio between anapplied force and the displacement that results from the applied force.Effective stiffness is measured herein using the Vibration DisplacementTest (“VDT”).

In some embodiments, the at least one support layer has an effectivestiffness of 0.01 Pa/nm to 15 Pa/nm. In some embodiments, the at leastone support layer has an effective stiffness of 0.5 Pa/nm to 5 Pa/nmwhen measured using the VDT. In some embodiments, the at least onesupport layer has an effective stiffness of 1 Pa/nm to 2 Pa/nm whenmeasured using the VDT.

In some embodiments, the at least one support layer has an effectivestiffness of 0.05 Pa/nm to 0.1 Pa/nm when measured using the VDT. Insome embodiments, the at least one support layer has an effectivestiffness of 0.05 Pa/nm to 0.5 Pa/nm when measured using the VDT. Insome embodiments, the at least one support layer has an effectivestiffness of 0.05 Pa/nm to 1 Pa/nm when measured using the VDT. In someembodiments, the at least one support layer has an effective stiffnessof 0.05 Pa/nm to 2 Pa/nm when measured using the VDT. In someembodiments, the at least one support layer has an effective stiffnessof 0.05 Pa/nm to 5 Pa/nm when measured using the VDT. In someembodiments, the at least one support layer has an effective stiffnessof 0.05 Pa/nm to 15 Pa/nm when measured using the VDT. In someembodiments, the at least one support layer has an effective stiffnessof 0.05 Pa/nm to 25 Pa/nm when measured using the VDT.

In some embodiments, the at least one support layer has an effectivestiffness of 0.1 Pa/nm to 25 Pa/nm when measured using the VDT. In someembodiments, the at least one support layer has an effective stiffnessof 0.5 Pa/nm to 25 Pa/nm when measured using the VDT. In someembodiments, the at least one support layer has an effective stiffnessof 1 Pa/nm to 25 Pa/nm when measured using the VDT. In some embodiments,the at least one support layer has an effective stiffness of 2 Pa/nm to25 Pa/nm when measured using the VDT. In some embodiments, the at leastone support layer has an effective stiffness of 5 Pa/nm to 25 Pa/nm whenmeasured using the VDT. In some embodiments, the at least one supportlayer has an effective stiffness of 15 Pa/nm to 25 Pa/nm when measuredusing the VDT.

In some embodiments, the at least one support layer comprises at leastone metal. In some embodiments, the at least one support layer comprisesat least one polymer. In some embodiments, the at least one supportlayer comprises fiberglass. In some embodiments, the at least onesupport layer comprises at least one or more metals, one or morepolymers, or fiberglass. In some embodiments, there is a single supportlayer. In some embodiments there are at least two support layers. Insome embodiments each support layer is the same material. In someembodiments each support layer is a different material. In someembodiments, the first support layer type is a first metal and thesecond support layer type is a second metal. In some embodiments, thefirst support layer type is a metal and the second support layer type isa polymer or fiberglass. In some embodiments the first support layertype is a first polymer and the second support layer type is a secondpolymer. In some embodiments, the first support layer and the secondsupport layers are both fiberglass.

In some embodiments the at least one metal comprises one or more ofzinc, nickel, chromium, vanadium, molybdenum, manganese, copper, iron,aluminum, titanium, combinations and alloys thereof. In someembodiments, the metal comprises an alloy such as carbon steel,stainless steel, bronze, brass, combinations thereof, or compositealloys thereof.

In some embodiments, the at least one polymer of the support layer is inthe form of a woven or nonwoven material. In some embodiments, the atleast one polymer of the support layer comprises one or more of:extruded plastic, polyethylene terephthalate (PET), polyphenylenesulfide (PPS), polybutylene terephthalate (PBT), polyether ether ketone(PEEK); polypthalamides (PPA), acetal homopolymers; polyethyleneterephthalate (PET), one or more thermoset epoxies, or one or morethermoset elastomers. In some embodiments, the support layer mightinclude multiple components with different melting temperature.

In some embodiments, the at least one support layer is adhered to thepolymer membrane by one or more adhesives. In some embodiments, theadhesive comprises one or more high melt thermoplastics. In oneembodiment, the high melt thermoplastic material may includepoly(ethylene-co-tetrafluoroethylene-co-hexafluoropropylene (EFEP),tetrafluoroethylene hexafluoropropylene vinylidene fluoride (THV),poly(tetrafluoroethylene-co-hexafluoro-propylene) (FEP), perfluoroalkoxy(PFA), Ethylene tetrafluoroethylene (ETFE), PVC resins, nitrile rubber,or combinations thereof.

In some embodiments, the polymer membrane is laminated to the at leastone support layer. In some embodiments the lamination is laserlamination. In some embodiments the lamination is thermal lamination. Insome embodiments, the polymer membrane is sandwiched between one surfaceof a first support layer and one surface of a second support layer.

In some embodiments, the assembly has an effective stiffness of 0.0002Pa/nm to 3000 Pa/nm when measured using the VDT. In some embodiments,the assembly has an effective stiffness of 0.0002 Pa/nm to 1000 Pa/nmwhen measured using the VDT. In some embodiments, the assembly has aneffective stiffness of 0.0002 Pa/nm to 100 Pa/nm when measured using theVDT. In some embodiments, the assembly has an effective stiffness of0.198 Pa/nm to 29.8 Pa/nm when measured using the VDT. In someembodiments, the assembly has an effective stiffness of 0.001 Pa/nm to500 Pa/nm when measured using the VDT. In some embodiments, the assemblyhas an effective stiffness of 0.01 Pa/nm to 250 Pa/nm when measuredusing the VDT. In some embodiments, the assembly has an effectivestiffness of 0.05 Pa/nm to 100 Pa/nm when measured using the VDT. Insome embodiments, the assembly has an effective stiffness of 0.1 Pa/nmto 50 Pa/nm when measured using the VDT. In some embodiments, theassembly has an effective stiffness of 1 Pa/nm to 25 Pa/nm when measuredusing the VDT. In some embodiments, the assembly has an effectivestiffness of 5 Pa/nm to 10 Pa/nm when measured using the VDT. In someembodiments, the assembly has an effective stiffness of 0.0002 Pa/nm to100 Pa/nm when measured using the VDT. In some embodiments, the assemblyhas an effective stiffness of 0.0006 Pa/nm to 29.8 Pa/nm when measuredusing the VDT.

In some embodiments, the assembly has an effective stiffness of 0.0005Pa/nm to 30 Pa/nm when measured using the VDT. In some embodiments, theassembly has an effective stiffness of 0.005 Pa/nm to 25 Pa/nm whenmeasured using the VDT. In some embodiments, the assembly has aneffective stiffness of 0.05 Pa/nm to 20 Pa/nm when measured using theVDT. In some embodiments, the assembly has an effective stiffness of 0.1Pa/nm to 15 Pa/nm when measured using the VDT. In some embodiments, theassembly has an effective stiffness of 1 Pa/nm to 10 Pa/nm when measuredusing the VDT.

In some embodiments, the assembly has an effective stiffness of 0.15Pa/nm to 32 Pa/nm when measured using the VDT. In some embodiments, theassembly has an effective stiffness of 0.3 Pa/nm to 16 Pa/nm. In someembodiments, the assembly has an effective stiffness of 0.6 Pa/nm to 8Pa/nm when measured using the VDT. In some embodiments, the assembly hasan effective stiffness of 1 Pa/nm to 4 Pa/nm when measured using theVDT. In some embodiments, the assembly has an effective stiffness of 2Pa/nm to 3 Pa/nm when measured using the VDT.

In some embodiments, the assembly has an effective stiffness of 0.15Pa/nm to 16 Pa/nm when measured using the VDT. In some embodiments, theassembly has an effective stiffness of 0.15 Pa/nm to 8 Pa/nm whenmeasured using the VDT. In some embodiments, the assembly has aneffective stiffness of 0.15 Pa/nm to 4 Pa/nm when measured using theVDT. In some embodiments, the assembly has an effective stiffness of0.15 Pa/nm to 3 Pa/nm when measured using the VDT. In some embodiments,the assembly has an effective stiffness of 0.15 Pa/nm to 2 Pa/nm whenmeasured using the VDT. In some embodiments, the assembly has aneffective stiffness of 0.15 Pa/nm to 1 Pa/nm when measured using theVDT. In some embodiments, the assembly has an effective stiffness of0.15 Pa/nm to 0.6 Pa/nm. when measured using the VDT. In someembodiments, the assembly has an effective stiffness of 0.15 Pa/nm to0.3 Pa/nm when measured using the VDT.

In some embodiments, the assembly has an air flow resistance rangingfrom 100 to 800,000 Rayls. In some embodiments, the assembly has an airflow resistance ranging from 200 to 400,000 Rayls. In some embodiments,the assembly has an air flow resistance ranging from 400 to 200,000Rayls. In some embodiments, the assembly has an air flow resistanceranging from 800 to 100,000 Rayls. In some embodiments, the assembly hasan air flow resistance ranging from 1600 to 50,000 Rayls. In someembodiments, the assembly has an air flow resistance ranging from 3200to 25,000 Rayls. In some embodiments, the assembly has an air flowresistance ranging from 6400 to 10,000 Rayls. In some embodiments, theassembly has an air flow resistance ranging from 8000 to 9000 Rayls.

In some embodiments, the assembly has an air flow resistance rangingfrom 100 to 50,000 Rayls. In some embodiments, the assembly has an airflow resistance ranging from 200 to 20,000 Rayls. In some embodiments,the assembly has an air flow resistance ranging from 400 to 10,000Rayls. In some embodiments, the assembly has an air flow resistanceranging from 800 to 5000 Rayls. In some embodiments, the assembly has anair flow resistance ranging from 1600 to 2500 Rayls.

In some embodiments, the assembly has an air flow resistance rangingfrom 100 to 20,000 Rayls. In some embodiments, the assembly has an airflow resistance ranging from 100 to 10,000 Rayls. In some embodiments,the assembly has an air flow resistance ranging from 100 to 5000 Rayls.In some embodiments, the assembly has an air flow resistance rangingfrom 100 to 2500 Rayls. In some embodiments, the assembly has an airflow resistance ranging from 100 to 1600 Rayls. In some embodiments, theassembly has an air flow resistance ranging from 100 to 800 Rayls. Insome embodiments, the assembly has an air flow resistance ranging from100 to 400 Rayls. In some embodiments, the assembly has an air flowresistance ranging from 100 to 200 Rayls.

In some embodiments, the assembly has an air flow resistance rangingfrom 10,000 to 800,000 Rayls. In some embodiments, the assembly has anair flow resistance ranging from 20,000 to 400,000 Rayls. In someembodiments, the assembly has an air flow resistance ranging from 40,000to 200,000 Rayls. In some embodiments, the assembly has an air flowresistance ranging from 80,000 to 100,000 Rayls.

In some embodiments, the assembly has an air flow resistance rangingfrom 50,000 to 800,000 Rayls. In some embodiments, the assembly has anair flow resistance ranging from 100,000 to 800,000 Rayls. In someembodiments, the assembly has an air flow resistance ranging from200,000 to 800,000 Rayls. In some embodiments, the assembly has an airflow resistance ranging from 400,000 to 800,000 Rayls.

In some embodiments, the predominantly resistive acoustic behavior is aresult of the effective stiffness (as described herein) of the at leastone support layer of the assembly. The phase angle of the acousticimpedance of the assembly is measured herein by the Impedance TubeTransfer Matrix Test (“ITTMT”) that is described in Test Proceduressection.

As used herein, the term “predominantly resistive” means that theassembly is configured to provide a phase angle of +45 degrees to −45degrees over a frequency range of 50 to 20,000 Hz as measured by theITTMT. In some embodiments, the assembly is configured to provide aphase angle of +30 degrees to −30 degrees over a frequency range of 500to 20,000 Hz as measured by the ITTMT. In some embodiments, the assemblyis configured to provide a phase angle of +15 degrees to −15 degreesover a frequency range of 50 to 20,000 Hz as measured by the ITTMT. Insome embodiments, the assembly is configured to provide a phase angle of+5 degrees to −5 degrees over a frequency range of 500 to 20,000 Hz asmeasured by the ITTMT. In some embodiments, the assembly is configuredto provide a phase angle of +1 degree to −1 degree over a frequencyrange of 50 to 20,000 Hz as measured by the ITTMT.

In some embodiments, the assembly is configured to provide a phase angleof +45 degrees to −45 degrees over a frequency range of 100 to 20,000 Hzas measured by the ITTMT. In some embodiments, the assembly isconfigured to provide a phase angle of +45 degrees to −45 degrees over afrequency range of 200 to 20,000 Hz as measured by the ITTMT. In someembodiments, the assembly is configured to provide a phase angle of +45degrees to −45 degrees over a frequency range of 300 to 20,000 Hz asmeasured by the ITTMT. In some embodiments, the assembly is configuredto provide a phase angle of +45 degrees to −45 degrees over a frequencyrange of 400 to 20,000 Hz as measured by the ITTMT. In some embodiments,the assembly is configured to provide a phase angle of +45 degrees to−45 degrees over a frequency range of 500 to 20,000 Hz as measured bythe ITTMT.

In some embodiments, the assembly is configured to provide a phase angleof +45 degrees to −45 degrees over a frequency range of 1000 to 10,000Hz as measured by the ITTMT. In some embodiments, the assembly isconfigured to provide a phase angle of +45 degrees to −45 degrees over afrequency range of 2000 to 8000 Hz as measured by the ITTMT. In someembodiments, the assembly is configured to provide a phase angle of +45degrees to −45 degrees over a frequency range of 4000 to 5000 Hz asmeasured by the ITTMT

In some embodiments, the assembly is configured to provide a phase angleof +45 degrees to −45 degrees over a frequency range of 500 to 10,000 Hzas measured by the ITTMT. In some embodiments, the assembly isconfigured to provide a phase angle of +45 degrees to −45 degrees over afrequency range of 500 to 8000 Hz as measured by the ITTMT. In someembodiments, the assembly is configured to provide a phase angle of +45degrees to −45 degrees over a frequency range of 500 to 4000 Hz asmeasured by the ITTMT. In some embodiments, the assembly is configuredto provide a phase angle of +45 degrees to −45 degrees over a frequencyrange of 500 to 4000 H as measured by the ITTMT. In some embodiments,the assembly is configured to provide a phase angle of +45 degrees to−45 degrees over a frequency range of 500 to 2000 Hz. In someembodiments, the assembly is configured to provide a phase angle of +45degrees to −45 degrees over a frequency range of 500 to 1000 Hz asmeasured by the ITTMT.

In some embodiments, the assembly is configured to provide a phase angleof +45 degrees to −45 degrees over a frequency range of 1000 to 20,000Hz as measured by the ITTMT. In some embodiments, the assembly isconfigured to provide a phase angle of +45 degrees to −45 degrees over afrequency range of 2000 to 20,000 Hz as measured by the ITTMT. In someembodiments, the assembly is configured to provide a phase angle of +45degrees to −45 degrees over a frequency range of 4000 to 20,000 Hz asmeasured by the ITTMT. In some embodiments, the assembly is configuredto provide a phase angle of +45 degrees to −45 degrees over a frequencyrange of 8000 to 20,000 Hz as measured by the ITTMT. In someembodiments, the assembly is configured to provide a phase angle of +45degrees to −45 degrees over a frequency range of 10,000 to 20,000 Hz asmeasured by the ITTMT.

In some embodiments, the assembly is configured to provide a certainwater entry pressure (“WEP”) as measured in accordance with theCapillary Piston Test (“CPT”). The CPT is described herein in thesection titled “Test Procedures.” In some embodiments, the WEP describedherein is a result of the effective stiffness (as described herein) ofthe at least one support layer or the assembly.

In some embodiments, the assembly is configured to provide a water entrypressure ranging from 1 psi to 450 psi when measured in accordance withthe CPT. In some embodiments, the assembly is configured to provide awater entry pressure ranging from 2 psi to 200 psi when measured inaccordance with the CPT. In some embodiments, the assembly is configuredto provide a water entry pressure ranging from 5 psi to 100 psi whenmeasured in accordance with the CPT. In some embodiments, the assemblyis configured to provide a water entry pressure ranging from 10 psi to50 psi when measured in accordance with the CPT. In some embodiments,the assembly is configured to provide a water entry pressure rangingfrom 20 psi to 25 psi when measured in accordance with the CPT.

In some embodiments, the assembly is configured to provide a water entrypressure ranging from 10 psi to 350 psi when measured in accordance withthe CPT. In some embodiments, the assembly is configured to provide awater entry pressure ranging from 20 psi to 200 psi when measured inaccordance with the CPT. In some embodiments, the assembly is configuredto provide a water entry pressure ranging from 40 psi to 100 psi whenmeasured in accordance with the CPT. In some embodiments, the assemblyis configured to provide a water entry pressure ranging from 50 psi to80 psi when measured in accordance with the CPT. In some embodiments,the assembly is configured to provide a water entry pressure rangingfrom 60 psi to 70 psi when measured in accordance with the CPT.

In some embodiments, the assembly is configured to provide a water entrypressure ranging from 10 psi to 200 psi when measured in accordance withthe CPT. In some embodiments, the assembly is configured to provide awater entry pressure ranging from 10 psi to 100 psi when measured inaccordance with the CPT. In some embodiments, the assembly is configuredto provide a water entry pressure ranging from 10 psi to 80 psi whenmeasured in accordance with the CPT. In some embodiments, the assemblyis configured to provide a water entry pressure ranging from 10 psi to70 psi when measured in accordance with the CPT. In some embodiments,the assembly is configured to provide a water entry pressure rangingfrom 10 psi to 60 psi when measured in accordance with the CPT. In someembodiments, the assembly is configured to provide a water entrypressure ranging from 10 psi to 50 psi when measured in accordance withthe CPT. In some embodiments, the assembly is configured to provide awater entry pressure ranging from 10 psi to 40 psi when measured inaccordance with the CPT. In some embodiments, the assembly is configuredto provide a water entry pressure ranging from 10 psi to 20 psi whenmeasured in accordance with the CPT.

In some embodiments, the assembly is configured to provide a water entrypressure ranging from 20 psi to 350 psi when measured in accordance withthe CPT. In some embodiments, the assembly is configured to provide awater entry pressure ranging from 40 psi to 350 psi when measured inaccordance with the CPT. In some embodiments, the assembly is configuredto provide a water entry pressure ranging from 50 psi to 350 psi whenmeasured in accordance with the CPT. In some embodiments, the assemblyis configured to provide a water entry pressure ranging from 60 psi to350 psi when measured in accordance with the CPT. In some embodiments,the assembly is configured to provide a water entry pressure rangingfrom 70 psi to 350 psi when measured in accordance with the CPT. In someembodiments, the assembly is configured to provide a water entrypressure ranging from 80 psi to 350 psi when measured in accordance withthe CPT. In some embodiments, the assembly is configured to provide awater entry pressure ranging from 100 psi to 350 psi when measured inaccordance with the CPT. In some embodiments, the assembly is configuredto provide a water entry pressure ranging from 1.4 psi to 432 psi whenmeasured in accordance with the CPT. In some embodiments, the assemblyis configured to provide a water entry pressure ranging from 2.5 psi to336 psi when measured in accordance with the CPT. In some embodiments,the assembly is configured to provide a water entry pressure rangingfrom 0.95 psi to 142 psi when measured in accordance with the CPT.

In some embodiments, the assembly is configured to provide a water entrypressure ranging from 200 psi to 350 psi when measured in accordancewith the CPT.

In some embodiments, the assembly is configured to provide atransmission loss of from 3 dB to 50 dB over the frequency range of 50to 20,000 Hz as measured by the ITTMT. In some embodiments, the assemblyis configured to provide a transmission loss of from 3 dB to 50 dB overthe frequency range of 100 to 20,000 Hz as measured by the ITTMT. Insome embodiments, the assembly is configured to provide a transmissionloss of from 3 dB to 50 dB over the frequency range of 200 to 20,000 Hzas measured by the ITTMT. In some embodiments, the assembly isconfigured to provide a transmission loss of from 3 dB to 50 dB over thefrequency range of 500 to 20,000 Hz as measured by the ITTMT.

In some embodiments, the assembly is configured to provide atransmission loss of from 6 dB to 24 dB over the frequency range of 50to 20,000 Hz as measured by the ITTMT. In some embodiments, the assemblyis configured to provide a transmission loss of from 11 dB to 13 dB overthe frequency range of 50 to 20,000 Hz as measured by the ITTMT.

In some embodiments, the assembly is configured to provide atransmission loss of from 3 dB to 6 dB over the frequency range of 50 to20,000 Hz as measured by the ITTMT. In some embodiments, the assembly isconfigured to provide a transmission loss of from 3 dB to 11 dB over thefrequency range of 50 to 20,000 Hz as measured by the ITTMT. In someembodiments, the assembly is configured to provide a transmission lossof from 3 dB to 13 dB over the frequency range of 50 to 20,000 Hz asmeasured by the ITTMT. In some embodiments, the assembly is configuredto provide a transmission loss of from 3 dB to 24 dB over the frequencyrange of 50 to 20,000 Hz as measured by the ITTMT.

In some embodiments, the assembly is configured to provide atransmission loss of from 6 dB to 48 dB over the frequency range of 50to 20,000 Hz as measured by the ITTMT. In some embodiments, the assemblyis configured to provide a transmission loss of from 11 dB to 48 dB overthe frequency range of 50 to 20,000 Hz as measured by the ITTMT. In someembodiments, the assembly is configured to provide a transmission lossof from 13 dB to 48 dB over the frequency range of 50 to 20,000 Hz asmeasured by the ITTMT. In some embodiments, the assembly is configuredto provide a transmission loss of from 13 dB to 48 dB over the frequencyrange of 50 to 20,000 Hz as measured by the ITTMT. In some embodiments,the assembly is configured to provide a transmission loss of from 24 dBto 48 dB over the frequency range of 50 to 20,000 Hz as measured by theITTMT.

In some embodiments, the transmission loss of the assembly issubstantially constant as a function of frequency. As used herein,“substantially constant as a function of frequency” means that thetransmission loss does not vary by more than 1.5 dB/octave over thefrequency range of 50 to 20,000 Hz. The variance of transmission loss asa function of frequency can be determined by plotting transmission lossas a function of frequency. Frequencies on an x-axis of a plot oftransmission loss versus frequency can be scaled to octaves usinglogarithmic scaling. An example of a scaling procedure according to thepresent disclosure is described herein in the “Test Procedures” section.

In some embodiments, the transmission loss of the assembly issubstantially constant as a function of frequency, such that thetransmission loss does not vary by more than 1.5 dB/octave over thefrequency range of 50 to 20,000 Hz when measured by the Impedance TubeTransfer Matrix Test (“ITTMT”). In some embodiments, the transmissionloss of the assembly is substantially constant as a function offrequency, such that the transmission loss does not vary by more than1.5 dB/octave over the frequency range of 100 to 20,000 Hz when measuredby the Impedance Tube Transfer Matrix Test (“ITTMT”). In someembodiments, the transmission loss of the assembly is substantiallyconstant as a function of frequency, such that the transmission lossdoes not vary by more than 1.5 dB/octave over the frequency range of 300to 20,000 Hz when measured by the Impedance Tube Transfer Matrix Test(“ITTMT”). In some embodiments, the transmission loss of the assembly issubstantially constant as a function of frequency, such that thetransmission loss does not vary by more than 1.5 dB/octave over thefrequency range of 400 to 20,000 Hz when measured by the Impedance TubeTransfer Matrix Test (“ITTMT”). In some embodiments, the transmissionloss of the assembly is substantially constant as a function offrequency, such that the transmission loss does not vary by more than1.5 dB/octave over the frequency range of 500 to 20,000 Hz when measuredby the Impedance Tube Transfer Matrix Test (“ITTMT”).

In some embodiments, the transmission loss does not vary by more than1.25 dB/octave over the frequency range of 50 to 20,000 Hz when measuredby the Impedance Tube Transfer Matrix Test (“ITTMT”). In someembodiments, the transmission loss does not vary by more than 1dB/octave over the frequency range of 50 to 20,000 Hz when measured bythe Impedance Tube Transfer Matrix Test (“ITTMT”). In some embodiments,the transmission loss does not vary by more than 0.75 dB/octave over thefrequency range of 50 to 20,000 Hz when measured by the Impedance TubeTransfer Matrix Test (“ITTMT”). In some embodiments, the transmissionloss does not vary by more than 0.5 dB/octave over the frequency rangeof 50 to 20,000 Hz when measured by the Impedance Tube Transfer MatrixTest (“ITTMT”). In some embodiments, the transmission loss does not varyby more than 0.25 dB/octave over the frequency range of 50 to 20,000 Hzwhen measured by the Impedance Tube Transfer Matrix Test (“ITTMT”).

In some embodiments, the transmission loss varies by 0.25 dB/octave to1.5 dB/octave over the frequency range of 50 to 20,000 Hz when measuredby the Impedance Tube Transfer Matrix Test (“ITTMT”). In someembodiments, the transmission loss varies by 0.25 dB/octave to 1.25dB/octave over the frequency range of 50 to 20,000 Hz when measured bythe Impedance Tube Transfer Matrix Test (“ITTMT”). In some embodiments,the transmission loss varies by 0.25 dB/octave to 1 dB/octave over thefrequency range of 50 to 20,000 Hz when measured by the Impedance TubeTransfer Matrix Test (“ITTMT”). In some embodiments, the transmissionloss varies by 0.25 dB/octave to 0.75 dB/octave over the frequency rangeof 50 to 20,000 Hz when measured by the Impedance Tube Transfer MatrixTest (“ITTMT”). In some embodiments, the transmission loss varies by0.25 dB/octave to 0.5 dB/octave over the frequency range of 50 to 20,000Hz when measured by the Impedance Tube Transfer Matrix Test (“ITTMT”).

FIG. 1 depicts an exemplary embodiment of the present disclosure. Asshown, assembly 100 includes a porous polymer membrane 104 in contactwith support layer 102. The support layer 102 includes a plurality ofopenings 106 and the porous polymer membrane 104 includes a plurality ofpores (not shown).

FIG. 2 also depicts an exemplary embodiment of the present disclosure.As shown, assembly 200 includes a porous polymer membrane 204 in directcontact with support layers 202. The support layers 202 include aplurality of openings 206 and the porous polymer membrane 204 includes aplurality of pores (not shown). As shown, the porous polymer membrane204 is sandwiched between the support layers 202. The assembly 200 maycontain portions (e.g., portions 208) where the polymer membrane 204 isin contact with the support layers 202. In some embodiments, theplurality of openings 206 are uniform. In some embodiments, thethickness (not shown) of the support layers 202 is uniform. In someembodiments, the plurality of openings 206 are non-uniform. In someembodiments, the thickness (not shown) of the support layers 202 isnon-uniform.

Test Procedures

The following test procedures were used to generate the data in theexamples section. The test procedures described herein are not intendedto be limiting. The assembly, membrane, and support layer numbersdescribed in this section refer to the assembly, membrane, and supportlayer numbers of the Examples section, infra.

Thickness:

Thicknesses of the polymer membranes were measured herein using acommercially available Keyence LS-7010 M. Some membranes were less than1 um in thickness and could not be directly measured using the KeyenceLS-7010 M. Instead, the membranes were layered to achieve a thicknessgreater than 1 um, which was the lower detection limit of themeasurement system. The total thickness of the layered membranes werethen measured using the Keyence LS-7010M. The thickness of a singlelayer was determined by dividing the total thickness of the layeredsamples by the number of layers.

Flow Resistance:

Airflow was measured using an ATEQ D520 Airflow Tester. The stack-up ofthe samples were described for each example. In all configurations, theactive area was assumed to be 1.77e-6 m⁻². The pressure at which eachassembly was tested and resultant airflow was described herein in theExamples section. The airflow was measured in units of L/hr. Themeasured airflow was converted to flow resistance (Pa*s/m) as per theequation below

Flow Resistance

$\left( {{Pa}*{s/m}} \right) = {4.39e^{4}\frac{x({psi})}{y\left( \frac{L}{hr} \right)}}$

where x (psi) represents the air pressure used during the ATEQmeasurement, and y (L/hr) was the volume flow rate measured directly onthe ATEQ tester.

Young's Modulus:

Herein, Young's Moduli of the polymer membranes were measured inaccordance with ISO 527-1:2012.

Bubble Point:

Herein, bubble point was measured using the ASTM F316. 9599-1 method.

Mass Per Unit Area:

Herein, mass per unit area was measured in accordance with ASTMD3776/D3776M-09a.

Water Entry Pressure Testing (Capillary Piston Test (“CPT”)):

Water Entry Pressure (“WEP”) was measured using a capillary flowporometer, model number CFP-1500-AE, purchased commercially from PorousMaterials Inc. The tested sample was clamped by two polycarbonate platesin the lower piston in the tester. The top plate has a central hole of 8mm and an O-ring surrounding the hole for waterproofing. The bottomplate has a central hole of 1.5 mm. For certain sample assemblies (e.g.,12, 13, 15, 16, 17, 31, 32, 33, and 34), the samples were prepared asdescribed in each example, and the sample will be clamped by the top andbottom polycarbonate plates. For other sample assemblies, the material,or layers of different materials were cut into pieces large enough tocover the whole O-ring on the top polycarbonate plate and clamped by thetop and bottom polycarbonate plates. Before the test, deionized waterwas added to fill the 8 mm hole in the top plate. The compressionpressure was set to be 300 psi in the test program. The ramp rate of thepressure was 0.16 psi per second. The tester automatically andinstantaneously detects the pressure (WEP) when water enters into thesample.

Effective Stiffness Measurement:

Effective stiffness, k_(eff) (Pa/nm), was measured using the VibrationalDisplacement Test (“VDT”). The VDT includes the following: Samples wereacoustically excited at 4 different sound pressures and the vibrationaldisplacement at the center of the sample was measured. The excitationsound pressure was taken as the difference in sound pressure between thetwo microphones. The resulting data (i.e. the difference between thesound pressures in front of and behind the acoustic membrane assemblyvs. displacement) was plotted and a linear regression performed.Effective stiffness was taken as the slope of the line passing throughthe measured data points and represents the extent to which a supportedor unsupported sample assembly resists vibrational deformation inresponse to an applied acoustic plane wave. The vibrational displacementwas measured using an MSA-500 micro system analyzer obtainedcommercially from Polytec Inc. The acoustic excitation was a sine wavecentered at 200 Hz and generated by a JBL model 2426H compressiondriver. The output from the compression driver was necked down from 25.4mm to 1.5 mm using an aluminum cone in order to match the diameter ofthe sample. The sound pressure of the wave was measured directly belowand directly above the surface of the sample being tested using twoprobe microphones (model 377B26 microphones connected to a model 482CSeries Sensor Signal Conditioner, obtained commercially from PCBPiezotronics Inc.). Polytec PSV 9.3 software was used to acquire thevibrational displacement data.

Transmission Loss and Phase Testing:

Transmission loss and phase angle testing were performed by theImpedance Tube Transfer Matrix Test (“ITTMT”), which is a modifiedversion of ASTM-E2611-09—the standard test method for measuring normalincidence sound transmission loss and phase based on the 4 microphonetransfer matrix method. All modifications to ASTM-E2611-09 are set forthherein. An exemplary test set-up is shown in FIG. 3. The transfer matrixof the assembly was measured and we use T12 element of the transfermatrix as the acoustic impedance value for all the assemblies describedin the examples.

An impedance tube was used to make measurements across a frequency rangeof 500 Hz to 20,000 Hz. The inner diameter of the tube was 8 mm. Theimpedance tube was designed in accordance with ASTM E1050-12 and ASTME2611-09.A JBL 2426H compression driver was mounted at one end of thetube and powered by a Bruel and Kjaer Type 2735 amplifier connected to a31-band ART 351 graphic equalizer. The measurement system used 4 Brueland Kjaer Type 4138 microphones connected to a 4 channel Bruel and KjaerType 3160-A-042 LAN-XI Frontend with a generator output. Data wasacquired and processed using Bruel and Kjaer PULSE Labshop with Type7758 Acoustic Material Testing Software, version 21.

The sample assemblies that were tested had an inner diameter of 1.5 mm,which was smaller than the inner diameter of the impedance tube. A pairof conical adapters was therefore required in order to mount the sampleassemblies. The convergent cone had an inlet diameter of 8 mm and anoutlet diameter of 1.5 mm. The divergent cone had an inlet diameter of1.5 mm and an outlet diameter of 8 mm.

When using conical adapters, additional processing of the data wasrequired to account for the converging geometry of the cones.Theoretical equations were derived to calculate the transfer matrices ofthe conical adapters and can be found in the literature (Hua, X. andHerrin, D., “Practical Considerations when using the Two-Load Method toDetermine the Transmission Loss of Mufflers and Silencers,” SAE Int. J.Passeng. Cars—Mech. Syst. 6(2):1094-1101, 2013 & Mechel, F. P. (2008).Formulas of Acoustics. New York, N.Y.: Springer).

Transmission Loss Testing Before and after Pressure Testing:

Some sample assemblies were subjected to the following Air Pressure Testprocedure. The purpose of this test was to replicate the pressureexerted on a membrane assembly in a device that was submerged in a givendepth of water for a given duration of time. A transmission lossspectrum was measured before the pressure test and then remeasuredimmediately after the pressure test. The change in transmission loss,ΔTL (dB), due to the pressure test was calculated by subtracting theinitial pre-test transmission loss from the post-test transmission loss.

Air Pressure Test:

Pressure testing was performed by placing a sample assembly onto a baseplate. A top plate was then added and bolted down to hold the sampleassemblies securely in place. The testing conditions (ramp rate,pressure, hold time) were all controlled using a calibrated,programmable pressure box that was built in-house. The pressure box wascapable of generating pressures ranging from 1 psi to 145 psi inincrements of 0.5 psi. The pressurized line of air was connected to thebase plate such that the pressure test occurred at the bottom surface ofthe membrane. Unless otherwise noted, each sample assembly was orientedsuch that the membrane was positioned between the base plate of the testfixture and the support layer of the sample assembly. Pressure testingwas performed by increasing the pressure from 0 psi to targeted pressurewith a 2.5 psi/sec ramp rate. After the targeted pressure was reached,the pressure was held constant for 10-minutes hold. Once the test wascomplete, the sample assemblies were removed from the fixture and thetransmission loss was remeasured.

Transmission Loss Testing with Compression:

Some transmission loss (“TL”) measurements were performed as a functionof compression force applied to the sample assemblies.

Compression testing was performed using an Economical Load and Force(ELF) Measurement System (purchased commercially from Tekscan) with aFlexiForce A201 force sensor calibrated across a 0-111 Newtonmeasurement range. A fixture was designed to apply controlledcompression force to samples during transmission loss and phase testing.A schematic drawing of this fixture is shown in FIG. 4. The forcesensors were attached to the front plate using 4983 double sidedpressure sensitive adhesive (purchased commercially from Tesa TapeInc.).

Once the sample assemblies to be tested was mounted between the left andright plates of the compression fixture on the impedance tube assembly,the front plate was attached via a set of 4-40 flat head screws. Thecompression force is increased or decreased by tightening or looseningthese flat head screws, respectively. Once a target compression forcewas reached, a transmission loss measurement was performed. After themeasurement the screws were loosened to return the compression force to0 Newtons and the process was repeated at progressively highercompression levels.

Procedure for Calculating % Contact:

For support layers 1-6, 13, and 14, because of the periodicity orrandomness of the support structure, the contact percentage can bedetermined from a representative area smaller than the total activearea. A topography scan of a portion of support can be performed usingan optical profilometer (Polytec TopMap μLab), from themembrane-contacting side. The scanned topography in the depth range of20 um from the top was projected to a plane parallel to the support. Theprojected area will be larger than or equal to the area of physicalcontact between the membrane and support. The ratio between theprojected area and the area of field-of-view of the topography scan wascalculated using software ImageJ and can be considered as upper bound ofcontact percentage.

For support layer 7-12, within the active area, the area of physicalcontact between the membrane and support will be smaller than or equalto the total active area minus the area of perforations. The upper boundof contact percentage can be calculated as

${\%\mspace{14mu}{contract}\mspace{14mu}{area}} = {{\frac{{{Total}\mspace{14mu}{area}} - {{Area}\mspace{14mu}{of}\mspace{14mu}{Perforations}}}{{Total}\mspace{14mu}{Area}}*100} = {\frac{D^{2} - {nd}^{2}}{D^{2}}*100}}$where n is the number of perforations, d is the diameter of eachperforation and D is the diameter of the active area, which is 1.5 mmfor all sample assemblies. The diameter of each perforation was measuredusing an optical microscope (model VHX-5000, purchased commercially fromKeyence Corporation).

FIG. 5 depicts a micrograph showing the top-most 20 um of supportlayer 1. The dark regions in the image correspond to the fibers of thewoven mesh and represent the areas of the support layer that come intocontact with the membrane. The white regions in the image correspond toopen area.

FIG. 6 depicts an optical micrograph showing the top-most 20 um ofsupport layer 5. The dark areas correspond to the non-woven fibers. Thedark regions in the image correspond to the fibers of the non-wovensupport and represent the areas of the support layer that come intocontact with the membrane. The white regions in the image correspond toopen area.

Procedure for Calculating % Open Area:

The % Open area can be calculated as% open area=100−% contact area

EXAMPLES

Preparation of Sample Assemblies

The following table outlines properties of exemplary membranes that areused in the foregoing examples. These properties are merely exemplaryand not intended to be limiting.

TABLE 1 Properties of polymer membranes: Air Water Flow Entry Mass MaxMem- Thick- Resistance Effective Young's Pressure per Bubble Pore braneness (MKS Stiffness Modulus WEP Area Point Size # (μm) Rayls) (Pa/nm)(MPa) (psi) (g/m²) (psi) (μm) 1 9.4 4825 0.0044 31.1 20.2 1.83 16.6 0.732 13.3 12626 0.0053 29.6 43.8 3.74 30.1 0.40 3 15 49428 0.0405 48.3110.8 7.4 56 0.22 4 1.2 3304 0.0006 359 12.4 0.24 31.9 0.38 5 0.0606 2260.0009 Not Not 0.009 Not Not measured measured measured measured 60.1545 218 0.0007 Not 2.5 0.029 Not Not measured measured measured 7125.5 1836 0.0587 4 10.8 5.34 1.514 7.96 8 1.75 1864 0.0036 72.63 11.60.1679 13.56 0.89 9 0.83 919 0.0022 100.52 5.8 0.0953 4.85 2.49

Polymer membranes # s 1-9 above were prepared according to the followingmethods.

TABLE 2 Membrane Preparation Methods Membrane # Preparation Method 1Prepared according to the general teachings of U.S. Pat. No. 3,953,566.2 Prepared according to the general teachings of U.S. Pat. No. 3,953,5663 Prepared according to the general teachings of U.S. Pat. Nos.3,953,566 and 6,541,589 4 Prepared according to the general teachings ofU.S. Pat. Nos. 3,953,566 and 9,775,933 5 Prepared according to thegeneral teachings of U.S. Pat. No. 3,953,566 Membrane thickness wasmeasured as follows. 128 individual layers were stacked together and athickness of 7.76 μm was measured as described herein. The thickness ofa single layer was determined by dividing the total thickness by thenumber of layers. The thickness of this membrane was determined to be60.6 nm 6 Prepared according to the general teachings of U.S. Pat. No.3,953,566. Membrane thickness was measured as follows. 32 individuallayers were stacked together and a thickness of 4.95 μm was measured asdescribed herein. The thickness of a single layer was determined bydividing the total thickness by the number of layers. The thickness ofthis membrane was determined to be 154.5 nm 7 Prepared according to thegeneral teachings of U.S. Pat. Nos. 3,953,566 and 5,814,405. 8 Preparedaccording to the general teachings of U.S. Pat. No. 3,953,566 9 Preparedaccording to the general teachings of U.S. Pat. Nos. 3,953,566. Membranethickness was measured as follows. 2 individual layers were carefullystacked together and a thickness of 1.66 μm was measured as describedherein. The thickness of a single layer was determined by dividing thetotal thickness by the number of layers. The thickness of this membranewas determined to be 0.83 μm

The following table outlines properties of exemplary support layers thatare used in the foregoing examples. These properties are merelyexemplary and not intended to be limiting.

TABLE 3 Properties of support layers: Largest Air-Flow EffectiveDimension Resistance % of Single Effective Support Support Material (MKSOpen % Opening Thickness Stiffness Layer # Layer Type Composition Rayl)Area Contact (μm) (μm) (Pa/nm) 1 Woven PET 54 74.24 25.76 105 64 1.053 2Woven PET 79 52.32 47.68 33 40 0.243 3 Woven PET 171 37.27 62.73 20 700.792 4 Bi- Co-PET 43 87.97 12.03 330 80 1.163 Component Sheath w MeshPET Core 5 Non Woven Co-Polyester 67 83.16 16.84 350 127 0.844 6Apertured Polyethylene 157 77.68 22.32 220 109 0.066 Film 7 PerforatedBrass 704 9 91 96 410 22.64 Plate (Perforations: 19 × 100 μm) 8Perforated Brass 186 24 76 96 410 21.90 Plate (Perforations: 56 × 100μm) 9 Perforated Fiberglass 753 9 91 100 381 4.38 Plate (Perforations:19 × 100 μm) 10 Perforated Fiberglass 613 26 74 175 381 1.42 Plate(Perforations: 19 × 175 μm) 11 Perforated PET 1129 30.6 69.4 90 127 4.24Plate (Perforations: 85 × 90 μm) 12 Perforated PET 352 45.7 54.3 110 1302.9 Plate (Perforations: 85 × 110 μm) 13 Woven Nylon-6-6 1458 36.1363.87 10 64 0.255 14 Perforated Stainless Steel 1212 15.17 84.83 85 896.94 Plate

Certain non-limiting sample assemblies and comparative sample assembliesdescribed and tested herein were prepared as follows.

All example sample assemblies (with the exception of sample assembly 12and 13) and comparative sample assemblies are comprised of at least oneadhesive-backed fiberglass sample carrier, referred to simply asfiberglass sample carriers from this point forward. The fiberglasssample carriers were prepared by applying a double-sided pressuresensitive adhesive to one side of a fiberglass sheet (purchasedcommercially from McMaster-Carr, product #1331T37). Thefiberglass/adhesive sheets were then laser cut into coupons. A 1.5 mmdiameter hole was then fabricated in the center that aligned with theinner bore of the impedance tube and corresponds to the active area ofthe sample to be measured.

Comparative Sample Assemblies:

Certain non-limiting comparative sample assemblies were prepared asfollows: A piece of membrane was positioned on a smooth and levelsurface so that the membrane was flat and free of any wrinkled. Theadhesive release liner was removed from a pre-cut fiberglass samplecarrier to expose the adhesive. With adhesive layer exposed, the samplecarrier was gently placed onto the membrane and any excess membrane wascut away from the perimeter of the sample carrier. The sample carrierwas then placed onto an alignment jig with membrane side facing up. Therelease liner was removed from a second fiberglass sample carrier andplaced onto the alignment jig with adhesive side facing down, towardsthe membrane. Low pressure (manually applied and not measured) wasapplied to bring the bottom and top sample carriers together to form anassembly having the following stack up: fiberglass samplecarrier/adhesive/membrane/adhesive/fiberglass sample carrier. The stackup for comparative sample assemblies are shown in Table 4.

Sample Assemblies

Certain non-limiting sample assemblies with perforated adhesive-backedfiberglass support layers (e.g., Assemblies 15-17, 33, 34) were preparedaccording the following procedure. Perforated adhesive-backed fiberglasssupport layers were fabricated in a similar manner as adhesive-backedfiberglass sample carriers (described above), with the exception thatmultiple small diameter perforations (openings) were made instead of asingle large 1.5 mm diameter hole. The number of perforations and theirdiameters are shown in Table 3. Sample assemblies were then prepared asdescribed herein with the exception that one of the fiberglass samplecarriers was substituted with a pre-cut adhesive-backed perforatedfiberglass support, referred to simply as a perforated fiberglasssupport layer from this point forward. The stack up for these assembliesare shown in Table 3.

Certain non-limiting sample assemblies with woven and/or non-wovensupport layers (e.g., Assemblies 1-11, 14, 18-30) were prepared asfollows. Woven and non-woven support materials were cut from the rollinto small (6 mm×6 mm) square pieces and set aside. The adhesive releaseliner was removed from a pre-cut fiberglass sample carrier and adheredto a pre-cut square of the support material such that the supportcovered the 1.5 mm diameter hole at the center of the fiberglass samplecarrier. With a majority of the adhesive still exposed, the polymermembrane was then attached to the sample carrier. The fiberglass samplecarrier with the support layer and membrane attached was then placedmembrane side up on an alignment jig. The adhesive release liner from asecond fiberglass sample carrier was removed and placed adhesive sidedown onto the alignment jig. Light pressure was applied to bring thebottom and top sample carriers together to form an assembly having thefollowing stack up: fiberglasscarrier/adhesive/support/membrane/adhesive/fiberglass carrier. In somesample assemblies (e.g., assemblies 1-8, 10, 11, 14, 18, 20, 22, 23,25-28)) a second fiberglass sample carrier with support layer was usedto form an assembly having the following stack up: fiberglasscarrier/adhesive/support/membrane/support/adhesive/fiberglass carrier.Sample assembly 29 was pressurized at 17 psi for 10 minutes using thesame procedure described in the Test Procedures section to improve theattachment between the polymer membrane and the support layer. Refer toTable 3 for additional stack up information for assemblies with at leastone woven or non-woven support.

Certain non-limiting assemblies with perforated PET support layer(s)(e.g., Assemblies 31, 32) were prepared as follows: First, double sidedpressure sensitive adhesive was applied to one side of a PET sheet withthickness of 127-130 μm. The PET/adhesive sheets were then laser cutinto coupons. Perforations (openings) were formed in the 1.5 mm diametercircular area at the center of the coupon. The number of perforationsand their diameters are shown in Table 3. With the adhesive layerexposed, the coupon with perforations can be attached to a polymermembrane and act as a support layer. A fiberglass sample carrier wasthen attached to the opposite side of the membrane to form an assemblyhaving the following stack up: fiberglass samplecarrier/adhesive/membrane/adhesive/PET support.

Certain assemblies with brass support layers (e.g., Assemblies 12, 13)were prepared as follows. Brass coupons were prepared from sheetmaterial. Perforations (openings) were formed in the 1.5 mm diametercircular area at the center of the coupons. The number of perforationsand their diameters are shown in Table 3. The membrane was clampedbetween two brass support plates to form an adhesive-free assembly withthe following stack up: brass support/membrane/brass support. In thisprocedure, the perforations on both coupons align with accuracy.

Exemplary Lamination Procedure:

In some embodiments, the polymer membrane is laminated to the at leastone support layer. While lamination can be performed using any method,in some embodiments, the polymer membrane is laminated to the at leastone support layer using a mini hot roll laminator (model HL-200,purchased commercially from ChemInstruments Inc.). To improvehandleability, the support and membrane can be cut into 3-inch×6-inchstrips and placed between two pieces of 25.4-um-thick kapton (purchasedcommercially from DuPont) cut into strips slightly larger than themembrane and support layer. The sample assemblies can then be insertedbetween two rollers (a hot roll and a nip roll) and laminated. The stackup can be as follows: kapton/ePTFE/support layer/kapton. When wovenmeshes (e.g., product #34-33 and 6-105, Sefar Inc. Holding AG) are usedas a support layer, lamination can be performed at a temperature of 265C, a pressure of 40 psi between the hot roll and the nip roll and a linespeed of 45 cm/min. When bi-component mesh (e.g., product #28T1, UnitikaLtd.) is used as a support layer, lamination was performed at atemperature of 185° C., a pressure of 40 psi between the hot roll andnip roll and a line speed of 45 cm/min. When a non-woven material wasused (product #133, HDK Industries) as the support layer, lamination wasperformed at a temperature of 180 C, a pressure of 25 psi between thehot roll and the nip roll and a line speed of 400 cm/min.

The orientation can be such that the polymer membrane is closest to thehot roll and the support is closest to the nip roll. In someembodiments, a mesh support layer (product #28T1, Unitika) can belaminated onto the top and bottom surface of the membrane. The stack upfor these sample assemblies can be as follows: kapton/mesh supportlayer/ePTFE/mesh support layer/kapton. The sample assemblies wereinserted between the rollers a first time to laminate the mesh supportlayer to the top surface of the membrane. The sample assemblies can thenbe flipped over and inserted a second time to laminate the mesh supportlayer to the bottom surface of the membrane. After lamination, the topand bottom kapton layers can be removed.

TABLE 4 Exemplary configurations of Sample Assemblies: The followingtable lists the configuration of the assemblies used in the foregoingExamples. The “membrane #” and “support layer #” designated herein referto Tables 1 and 2 respectively. Assembly Support Membrane No. of supportAttachment # layer # # layers method Stackup 1 1 1 2 LayeredFiberglass/adhesive/support/polymer membrane/support/adhesive/fiberglass2 1 2 2 Layered Fiberglass/adhesive/support/polymermembrane/support/adhesive/fiberglass 3 1 3 2 LayeredFiberglass/adhesive/support/polymer membrane/support/adhesive/fiberglass4 1 4 2 Layered Fiberglass/adhesive/support/polymermembrane/support/adhesive/fiberglass 5 1 5 2 LayeredFiberglass/adhesive/support/polymer membrane/support/adhesive/fiberglass6 1 2 2 Layered Fiberglass/adhesive/support/polymermembrane/support/adhesive/fiberglass 7 1 2 2 LayeredFiberglass/adhesive/support/polymer membrane/support/adhesive/fiberglass8 1 2 2 Layered Fiberglass/adhesive/support/polymermembrane/support/adhesive/fiberglass 9 1 2 1 LayeredFiberglass/adhesive/polymer membrane /support/adhesive/fiberglass 10 1 22 Layered Fiberglass/adhesive/support/polymermembrane/support/adhesive/fiberglass 11 1 3 2 LayeredFiberglass/adhesive/support/polymer membrane/support/adhesive/fiberglass12 8 2 2 Layered Support/polymer membrane/support 13 7 2 2 LayeredSupport/polymer membrane/support 14 1 3 2 LayeredFiberglass/adhesive/support/polymer membrane/support/adhesive/fiberglass15 9 2 1 Adhesive Fiberglass/adhesive/polymer membrane/adhesive/support16 9 2 1 Adhesive Fiberglass/adhesive/polymer membrane/adhesive/support17 9 3 1 Adhesive Fiberglass/adhesive/polymer membrane/adhesive/support18 3 2 2 Layered Fiberglass/adhesive/support/polymermembrane/support/adhesive/fiberglass 19 2 3 1 LaminatedFiberglass/adhesive/polymer membrane/support/adhesive/fiberglass 20 3 12 Layered Fiberglass/adhesive/support/polymermembrane/support/adhesive/fiberglass 21 4 3 1 LaminatedFiberglass/adhesive/polymer membrane/support/adhesive/fiberglass 22 4 32 Laminated Fiberglass/adhesive/support/polymermembrane/support/adhesive/fiberglass 23 5 2 2 LayeredFiberglass/adhesive/support/polymer membrane/support/adhesive/fiberglass24 5 7 1 Laminated Fiberglass/adhesive/polymermembrane/support/adhesive/fiberglass 25 1 2 2 LayeredFiberglass/adhesive/support/polymer membrane/support/adhesive/fiberglass26 6 2 2 Layered Fiberglass/adhesive/support/polymermembrane/support/adhesive/fiberglass 27 13 8 2 LayeredFiberglass/adhesive/support/polymer membrane/support/adhesive/fiberglass28 13 9 2 Layered Fiberglass/adhesive/support/polymermembrane/support/adhesive/fiberglass 29 14 8 1 LayeredFiberglass/adhesive/polymer membrane/support/adhesive/fiberglass 30 4 41 Laminated Fiberglass/adhesive/polymermembrane/support/adhesive/fiberglass 31 11 4 1 AdhesiveFiberglass/adhesive/polymer membrane/adhesive/support 32 12 4 1 AdhesiveFiberglass/adhesive/polymer membrane/adhesive/support 33 10 4 1 AdhesiveFiberglass/adhesive/polymer membrane/adhesive/support 34 9 6 1 AdhesiveFiberglass/adhesive/polymer membrane/adhesive/support

TABLE 5 Comparative Sample Assemblies: The following table lists theconfiguration of the comparative sample assemblies used in the foregoingExamples. Comparative No. of Sample Support Membrane support AttachmentAssembly # layer # # layers method Stackup  1c None 1 0 UnsupportedFiberglass/adhesive/polymer   membrane/adhesive/fiberglass  2c None 2 0Unsupported Fiberglass/adhesive/polymer   membrane/adhesive/fiberglass 3c None 3 0 Unsupported Fiberglass/adhesive/polymer  membrane/adhesive/fiberglass  4c None 4 0 UnsupportedFiberglass/adhesive/polymer   membrane/adhesive/fiberglass  5c None 5 0Unsupported Fiberglass/adhesive/polymer   membrane/adhesive/fiberglass 6c None 2 0 Unsupported Fiberglass/adhesive/polymer  membrane/adhesive/fiberglass  7c None 2 0 UnsupportedFiberglass/adhesive/polymer   membrane/adhesive/fiberglass  8c None 2 0Unsupported Fiberglass/adhesive/polymer   membrane/adhesive/fiberglass 9c None 2 0 Unsupported Fiberglass/adhesive/polymermembrane/adhesive/fiberglass 10c None 3 0 UnsupportedFiberglass/adhesive/polymer membrane/adhesive/fiberglass 11c None 3 0Unsupported Fiberglass/adhesive/polymer membrane/adhesive/fiberglass 12cNone 3 0 Unsupported Fiberglass/adhesive/polymermembrane/adhesive/fiberglass 13c None 2 0 UnsupportedFiberglass/adhesive/polymer membrane/adhesive/fiberglass 14c None 8 0Unsupported Fiberglass/adhesive/polymer membrane/adhesive/fiberglass 15cNone 9 0 Unsupported Fiberglass/adhesive/polymermembrane/adhesive/fiberglass 16c None 4 0 UnsupportedFiberglass/adhesive/polymer membrane/adhesive/fiberglass 17c None 6 0Unsupported Fiberglass/adhesive/polymer membrane/adhesive/fiberglassProperties of Sample Assemblies and Comparative Sample Assemblies

The following table lists exemplary properties of certain sample andcomparative sample assemblies. All properties are measured as describedherein.

TABLE 6 Properties of certain Sample Assemblies: Pressure Waterdifference Entry Airflow for airflow Sample pressure Re- resistanceEffective Assembly WEP sistance test Stiffness # (psi) (Rayls) (psi)(Pa/nm)  1 59.940 4843 0.17 1.42  2, 6, 7, 120.318 15555 0.17 2.29  8,10, 25  3, 11, 14 199.4 62275 0.50 4.25  4 71.76 3227 0.17 25.5  5 Not204 0.17 1.623 measured  9 124.088 13845 0.17 2.2872 12 173.485 840140.7 29.8 13 209.813 357416 0.7 29.8 15, 16 224.790 67642 0.17 3.81 17336.360 434405 1 2.9 18 92.290 15760 0.17 0.739 19 156.745 125508 0.50.4524 20 57.123 5732 0.17 1.46 21 202.462 31058 0.5 0.6971 22 172.49949200 0.5 2.04 23 107.594 12050 0.17 1.52 24 10.908 2522 0.17 2.41 25120.318 15555 0.17 2.2872 26 149.459 14822 0.17 1.19 27 36.12 4705 0.170.657 28 12.732 3984 0.17 .657 29 80.114 2939 0.17 2.47 30 15.015 37920.17 .198 31 225.789 24012 0.17 2.32 32 211.157 12437 0.17 1.66 33162.933 31198 0.17 2.75 34 12.1 948 0.17 1.87

TABLE 7 Properties of certain Comparative Assemblies: Pressure WaterEntry difference used Comparative Pressure Airflow for airflow EffectiveSample (“WEP”) Resistance resistance test Stiffness Assembly # (psi)(Rayls) (psi) (Pa/nm)  1c 20.185 4825 0.17 0.0044  2c, 6c, 7c, 43.52612626 0.17 0.0053  8c, 9c, 13c  3c, 10c, 110.787 49428 0.5  0.0405  11c,12c  4c, 16c 12.413 3304 0.17 0.0006  5c Not 226 0.17  .0009 measured14c 11.576 1864 0.17 0.0036 15c 5.788 919 0.17 0.0022 17c 2.5 218 0.170.0007

Example 1—Non-Limiting Embodiments Exhibiting Constant AcousticTransmission and Resistive Behavior

For all the sample assemblies including the comparative sampleassemblies, transmission loss and phase angle testing was performed asdescribed in Test Procedures section.

The transmission loss data of the sample assemblies and comparativesample assemblies are shown in Table 8 at six discrete frequencies (500Hz, 1,000 Hz, 2,000 Hz, 5,000 Hz, 10,000 Hz, 20,000 Hz). Thetransmission loss vs. frequency spectra are shown in FIGS. 7 to 18.

TABLE 8 Transmission loss of sample assemblies and comparative sampleassemblies Transmission Loss (dB) Example # Assembly # 500 Hz 1,000 Hz2,000 Hz 5,000 Hz 10,000 Hz 20,000 Hz 1a 1 16.94 17.36 17.61 17.47 17.7817.89 1c 13.75 8.50 4.72 1.34 0.38 1.20 1b 2 23.13 24.16 24.27 24.2824.57 23.92 2c 18.91 15.17 10.35 3.83 1.09 2.27 1c 3 31.81 31.33 31.8031.83 32.03 27.75 3c 29.65 24.44 18.83 10.45 3.51 2.10 1d 4 11.39 11.5511.59 11.51 11.78 11.77 4c 12.02 8.79 4.93 1.42 0.53 0.34 1e 5 3.48 2.962.99 2.95 3.00 3.10 5c 1.81 1.79 1.74 0.77 0.20 0.25 1f 9 29.16 29.3629.21 28.60 27.67 23.93 9c 13.35 9.60 5.52 1.72 0.50 2.37 10 25.15 24.7125.00 25.23 25.87 25.80 1g 12 41.31 41.38 41.25 40.98 41.27 40.44 1g 1349.18 50.27 49.90 49.27 50.02 48.81 1h 18 25.81 25.80 26.00 26.10 26.8027.30 2c 18.91 15.17 10.35 3.83 1.09 2.27 1g 19 47.20 47.80 47.20 45.9042.40 36.90 1g 20 18.10 18.30 18.50 18.40 18.70 18.70 1g 21 37.70 37.8038.20 37.60 37.00 34.30 1g 23 23.30 23.00 23.70 23.60 23.50 22.30 1g 2415.20 15.30 15.50 15.50 15.60 14.20 1i 25 25.90 26.80 26.90 26.70 26.9027.20 13c 21.40 16.80 13.60 6.50 2.30 7.80 1g 26 25.19 25.76 25.69 25.0523.83 18.13 1j 27 15.92 16.42 16.32 15.91 15.53 12.62 14c 10.14 7.434.14 1.16 0.55 0.38 1k 28 14.27 14.39 14.23 13.92 13.75 12.27 15c 6.165.27 3.33 0.91 0.25 0.47 1g 29 15.44 15.78 15.81 15.52 15.52 15.31 1g 3017.80 18.16 18.04 17.46 16.36 13.80 1l 34 6.32 6.49 6.48 6.37 6.43 6.3617c 1.78 1.63 1.03 0.26 0.10 0.52

The phase angle data of the sample assemblies are shown in Table 10 atsix discrete frequencies (500 Hz, 1,000 Hz, 2,000 Hz, 5,000 Hz, 10,000Hz, 20,000 Hz). The raw phase angle vs. frequency spectra of the testedsample assemblies are shown in FIGS. 1 to 18.

TABLE 9 Phase angle of sample assemblies & comparative sampleassemblies: Phase Angle (degrees) Example # Assembly # 500 Hz 1,000 Hz2,000 Hz 5,000 Hz 10,000 Hz 20,000 Hz 1a 1 2.91 3.03 2.24 0.96 −0.78−2.74 1c −61.20 −64.00 −74.10 −76.00 −69.50 25.90 1b 2 6.50 3.69 1.56−2.71 −10.20 −23.50 2c −58.20 −68.40 −71.60 −75.10 −31.60 79.70 1c 33.82 0.74 −0.72 −7.73 −21.20 −42.90 3c −64.90 −74.30 −79.80 −84.10−86.10 82.90 1d 4 2.35 2.50 0.89 −1.23 −4.32 −12.60 4c −43.60 −60.80−75.20 −80.20 −86.07 −31.10 1e 5 −4.18 −1.72 0.73 −1.43 −2.86 −3.35 5c1.79 −10.40 −24.50 −60.60 −76.70 −28.50 1f 9 −0.36 −2.17 −6.46 −16.92−32.47 −51.92 9c −69.1 −68.8 −71.72 −68.65 56.05 75.94 10 9.39 7.79 4.651.22 −3.92 −15.72 1g 12 1.82 0.75 1.60 1.38 0.40 1.40 1g 13 3.33 2.18−0.20 0.87 1.59 3.52 1h 18 2.78 2.96 2.82 2.09 −1.48 −10.48 2c −58.20−68.40 −71.60 −75.10 −31.60 79.70 1g 19 −3.35 −5.98 −5.79 −23.22 −49.84−65.23 1g 20 0.71 2.56 1.58 0.07 −2.62 −6.27 1g 21 −2.07 −0.74 −3.30−10.81 −22.17 −37.77 1g 23 8.12 4.98 2.24 −6.42 −15.44 −38.18 1g 24 0.252.47 2.49 2.20 2.07 3.53 1i 25 1.16 1.99 1.13 −2.62 −7.19 −14.31 13c−44.64 −64.00 −75.08 −83.62 −86.59 81.72 1g 26 −3.14 −1.8 −6.67 −18.64−36.32 −58.63 1j 27 3.20 1.56 −1.22 −4.24 −10.59 −23.77 14c −36.35−52.86 −69.86 −79 −81.74 4.4508 1k 28 1.06 1.74 −0.15 −1.42 −5.00 −14.3015c −17.50 −32.67 −55.12 −72.93 −83.36 52.56 1g 29 2.94 2.60 1.31 1.81−1.27 3.87 1g 30 1.93 −0.35 −5.02 −14.89 −30.26 −42.71 1l 34 2.88 3.392.29 2.26 3.77 5.44 17c −14.70 −33.50 −52.50 −85.10 −84.80 −36.03

As shown, the sample assemblies exhibit phase angles falling within therange of +45 degrees to −45 at the tested frequencies, while thecomparative sample assemblies exhibit phase angles falling outside ofthe ranges of +45 degrees to −45 at some of the tested frequencies.

The slope of the transmission loss (in dB/Octave) for each sampleassembly and for each comparative sample assembly was measured through alinear regression over the discrete frequencies (500 Hz, 1,000 Hz, 2,000Hz, 5,000 Hz, 10,000 Hz, 20,000 Hz).

The frequencies were scaled to octaves using the following procedure:

The number of octaves between 500 Hz and 500 Hz is

${\log_{2}\left( \frac{500}{500} \right)} = 0$

The number of octaves between 500 Hz and 1000 Hz is

${\log_{2}\left( \frac{1000}{500} \right)} = 1$

The number of octaves between 500 Hz and 2000 Hz is

${\log_{2}\left( \frac{2000}{500} \right)} = 2$

The number of octaves between 500 Hz and 5000 Hz is

${\log_{2}\left( \frac{5000}{500} \right)} = {{3.3}2}$

The number of octaves between 500 Hz and 10,000 Hz is

${\log_{2}\left( \frac{10000}{500} \right)} = {{4.3}2}$

The number of octaves between 500 Hz and 20,000 Hz is

${\log_{2}\left( \frac{20000}{500} \right)} = {{5.3}2}$

The slope of the transmission loss spectrum can then be determined byperforming a linear regression on the transmission loss data over theabove-calculated octaves.

For comparative sample assemblies, the transmission loss value willdecrease with frequency in low frequency range and then increase withfrequency in high frequency range. The linear regression is performed inthe low frequency range for comparative sample assemblies. As shownbelow in Tables 10-11, for a given membrane, the slope of thetransmission loss of sample assemblies was closer to zero than the slopethe transmission loss of the comparative sample assemblies, indicatingthat the sample assemblies provided a more predominantly constant soundtransmission profile. Specifically, as illustrated by the non-limitingexamples below, in some embodiments of the present disclosure, theabsolute value of the slope of transmission loss is 1.5 dB/octave orless (i.e., the transmission loss ranges from is −1.5 dB/octave to 1.5dB/octave) over a 500 Hz to 20,000 Hz range. Put differently, in thenon-limiting examples of Table 10, transmission loss does not vary bymore than 1.5 dB/octave over the frequency range of 500 to 20,000 Hz.

TABLE 10 Slope of the transmission loss of sample assemblies andcomparative sample assemblies: Slope of TL (dB/Octave) over Example #Assembly # 500 Hz-20,000 Hz range 1a  1 0.152  1c −3.072 1b  2 .136  2c−4.293 1c  3 −.469  3c −5.528 1d  4 −0.127  4c −2.293 1e  5 −0.0473  5c−0.3932 1f  9 −0.833  9c −3.054 10 0.185 1g 12 −0.130 1g 13 −0.088 1h 180.277 2c −4.293 1g 19 −1.812 1g 20 0.107 1g 21 −0.524 1g 23 −0.092 1g 24−0.105 1i 25 0.170 13c −4.435 1g 26 −1.091 1j 27 −.512 14c −1.916 1k 28−0.321 15c −1.481 1g 29 −0.047 1g 30 −0.682 1l 34 −0.003 17c −0.435

Example 2—Non-Limiting Embodiments Exhibiting Improved PressureChallenge Resistance

For all the sample assemblies including the comparative sampleassemblies, transmission loss and phase angle testing was performed asdescribed in Test Procedures section. Sample assemblies were subjectedto a pressure test described in Table 11 below with a ten-minute holdtime.

TABLE 11 Test Pressures of sample assemblies and comparative sampleassemblies Example # Assembly # Challenge Pressure (psi) 2a  6 2.2  6c2.2 2b  7 14.5  7c 14.5 2c  8 43.5  8c 43.5 2d 11 43.5 10c 43.5 2e 1514.5 7c 14.5 2f 16 43.5 8c 43.5 2g 17 43.5 10c 43.5 2h 22 116 12c 116 2i27 17 29 17 2j 28 10 2k 31 10 32 10 33 10 16c 10

The pre vs. post test transmission loss and phase data was measured asdescribed in the Test Procedures Section. For the sample assemblies andthe comparative sample assemblies, the transmission loss before andafter the pressure test, as well as the relative change in transmissionloss, are shown in below in Tables 12 to 14 at six discrete frequencies(500 Hz, 1,000 Hz, 2,000 Hz, 5,000 Hz, 10,000 Hz, and 20,000 Hz). Theraw transmission loss and phase angle vs. frequency spectra are shown inFIGS. 19 to 29. As shown, for a given membrane, the change oftransmission loss before and after the pressure test is smaller thanthat for comparative sample assemblies, indicating that the sampleassemblies provided a more robust acoustic performance and improvedburst strength against pressure challenge.

TABLE 12 Transmission loss of sample assemblies and comparative sampleassemblies before pressure challenge Transmission Loss Before ChallengePressure Challenge (dB) Example Assembly Pressure 500 1,000 2,000 5,00010,000 20,000 # # (psi) Hz Hz Hz Hz Hz Hz 2a 6 2.2 24.67 25.16 25.3125.32 25.91 26.00 6c 2.2 20.40 15.91 10.58 3.75 0.59 1.50 2b 7 14.524.73 25.23 25.49 25.39 26.10 25.79 7c 14.5 23.23 18.32 13.81 6.25 1.892.36 2c 8 43.5 24.30 24.66 24.67 24.72 25.21 24.98 8c 43.5 21.64 17.4712.06 4.69 0.83 1.19 2d 11 43.5 32.44 31.92 31.72 31.53 30.69 26.10 10c43.5 18.78 14.29 9.09 2.38 0.31 5.55 2e 15 14.5 37.83 38.29 38.17 37.5037.67 37.88 7c 14.5 23.23 18.32 13.81 6.25 1.89 2.36 2f 16 43.5 36.8837.30 37.08 36.69 36.90 37.05 8c 43.5 21.64 17.47 12.06 4.69 0.83 1.192g 17 43.5 47.42 47.07 46.94 46.93 46.95 47.09 10c 43.5 18.78 14.29 9.092.38 0.31 5.55 2h 22 116 33.30 33.50 33.50 32.90 32.70 29.90 12c 11629.65 24.44 18.83 10.45 3.51 2.10 2i 27 17 15.92 16.42 16.32 15.91 15.5312.62 29 17 15.44 15.78 15.81 15.52 15.52 15.31 2j 28 10 14.27 14.3914.23 13.92 13.75 12.27 2k 31 10 30.42 30.10 29.60 29.20 29.30 28.40 3210 24.60 24.70 24.40 24.20 24.10 23.40 33 10 27.10 27.40 26.20 25.0024.20 23.10 16c 10 12.37 9.16 5.12 1.47 0.54 0.33

TABLE 13 Transmission loss of sample assemblies and comparative sampleassemblies after pressure challenge Challenge Transmission Loss AfterPressure Challenge (dB) Example Assembly Pressure 1,000 2,000 5,00010,000 20,000 # # (psi) 500 Hz Hz Hz Hz Hz Hz 2a 6 2.2 23.59 24.96 25.5225.61 26.63 26.36 2b 6c 2.2 13.48 9.00 5.33 1.64 1.12 4.56 7 14.5 24.1524.71 25.00 25.23 25.86 25.80 7c 14.5 13.35 9.60 5.52 1.72 0.50 2.31 2c8 43.5 24.40 23.94 24.30 24.40 25.10 25.14 8c 43.5 Burst Burst BurstBurst Burst Burst 2d 11 43.5 33.21 33.35 32.67 31.66 29.48 24.15 10c43.5 28.60 23.66 18.01 10.39 4.13 1.22 2e 15 14.5 38.77 39.80 38.8438.67 38.63 38.20 7c 14.5 13.35 9.60 5.52 1.72 0.50 2.31 2f 16 43.538.49 38.43 37.85 37.88 37.86 37.64 8c 43.5 Burst Burst Burst BurstBurst Burst 2g 17 43.5 49.50 49.51 49.75 50.14 49.66 49.19 10c 43.528.60 23.66 18.01 10.39 4.13 1.22 2h 22 116 31.70 31.80 32.30 33.7035.10 34.70 12c 116 Burst Burst Burst Burst Burst Burst 2i 27 17 16.6017.05 16.94 16.75 16.56 14.49 29 17 2.75 2.56 0.82 −0.83 −2.82 −0.06 2j28 10 14.28 14.65 14.54 14.35 14.24 13.27 2k 31 10 30.00 29.20 28.8028.50 28.20 27.50 32 10 25.30 25.70 25.50 25.10 24.50 23.10 33 10 25.5024.50 23.00 21.90 21.10 20.10 16c 10 3.04 1.11 1.32 0.64 0.34 0.51

TABLE 14 Change in transmission loss of sample assemblies andcomparative sample assemblies Challenue Change in Transmission Loss, ΔTL(dB) Example Assembly Pressure 500 1,000 2,000 5,000 10,000 20,000 # #(psi) Hz Hz Hz Hz Hz Hz 2a 6 2.2 −1.08 −0.20 0.21 0.29 0.72 0.36 6c 2.2−6.92 −6.91 −5.25 −2.11 0.53 3.06 2b 7 14.5 −0.58 −0.52 −0.49 −0.16−0.24 0.01 7c 14.5 −9.88 −8.72 −8.29 −4.53 −1.40 −0.05 2c 8 43.5 0.10−0.72 −0.37 −0.32 −0.11 0.16 8c 43.5 Burst Burst Burst Burst Burst Burst2d 11 43.5 0.77 1.43 0.95 0.13 −1.21 −1.95 10c 43.5 9.82 9.37 8.92 8.013.82 −4.33 2e 15 14.5 0.94 1.51 0.67 1.16 0.96 0.32 7c 14.5 −9.88 −8.72−8.29 −4.53 −1.40 −0.05 2f 16 43.5 1.61 1.13 0.77 1.19 0.96 0.59 8c 43.5Burst Burst Burst Burst Burst Burst 2g 17 43.5 2.08 2.45 2.81 3.21 2.712.11 10c 43.5 9.82 9.37 8.92 8.01 3.82 −4.33 2h 22 116 −1.60 −1.70 −1.200.80 2.40 4.80 12c 116 Burst Burst Burst Burst Burst Burst 2i 27 17 0.680.63 0.62 0.84 1.03 1.87 29 17 0.21 0.17 0.09 0.07 −0.08 −0.31 2j 28 100.01 0.26 0.31 0.43 0.49 1.00 2k 31 10 −0.42 −0.90 −0.80 −0.70 −1.10−0.90 32 10 0.70 1.00 1.10 0.90 0.40 −0.30 33 10 −1.60 −2.90 −3.20 −3.10−3.10 −3.00 16c 10 −9.33 −8.05 −3.80 −0.83 −0.20 0.18

Example 3—Non-Limiting Embodiments Exhibiting Improved CompressionResistance

Transmission loss and phase angle testing on assemblies undercompression was performed as described in section Test Proceduressection. Three different forces (5 N, 10 N, 20 N) were applied to thesample assembly 14 and comparative assembly 11c and the transmissionloss and phase angle are measured with the assemblies under compression.The transmission loss without compression force is also measured.

The raw transmission loss and phase angle vs. frequency spectra as afunction of compression force is shown in FIG. 30. The transmission lossand phase data are shown in Tables 15 and 16 at six discrete frequencies(500 Hz, 1,000 Hz, 2,000 Hz, 5,000 Hz, 10,000 Hz, and 20,000 Hz).

TABLE 15 Compressive forces applied to sample assemblies and comparativesample assemblies during transmission loss measurements Example #Assembly # Compressive Force (N) 3a 14 0, 5, 10, 20 11c 0, 5, 10, 20

TABLE 16 Transmission loss of sample assemblies and comparative sampleassemblies as a function of compressive force applied to each assemblyduring the measurement. Transmission Loss (dB) Compression 500 1,0002,000 5,000 10,000 20,000 Example # Assembly # Force (N) Hz Hz Hz Hz HzHz 3a 14  0 39.49 37.07 37.62 37.12 36.47 33.77  5 36.37 38.26 38.0437.82 36.78 33.44 10 37.02 39.02 38.62 38.06 37.16 33.32 20 39.16 40.5739.32 38.62 37.63 32.94 11c  0 26.14 23.17 17.51  9.06  1.98  4.39  530.67 26.77 21.30 13.24  5.19  3.27 10 39.10 32.39 26.40 18.39 11.59 3.02 20 43.70 37.44 31.65 24.10 16.44  5.91

TABLE 17 Change in transmission loss of sample assemblies andcomparative sample assemblies due to compression testing. Note that thechange in TL is relative to 0 N (no compression). Change in transmissionLoss (dB) Example Assembly Compression 5,000 10,000 20,000 # # Force (N)500 Hz 1,000 Hz 2,000 Hz Hz Hz Hz 3a 14 5 −3.12  1.19  0.42  0.70  0.31−0.33 10 −2.47  1.95  1.00  0.94  0.69 −0.45 20 −0.33  3.50  1.70  1.50 1.16 −0.83 11c 5 4.53  3.60  3.79  4.18  3.21 −1.12 10 12.96  9.22 8.89  9.33  9.61 −1.37 20 17.56 14.27 14.14 15.04 14.46 1.52

TABLE 18 Phase angle of sample assemblies and comparative sampleassemblies as a function of compressive force applied to each assemblyduring the measurement. Phase (degrees) Example Assembly Compression 5001,000 2,000 5,000 10,000 20,000 # # Force (N) Hz Hz Hz Hz Hz Hz 3a 14 0−4.74 −1.71 −3.24 −14.67 −29.72 −45.72 5 −0.30 −2.52 −4.89 −17.18 −36.49−52.36 10 −7.69 −2.43 −7.00 −16.44 −38.34 −54.07 20 −9.60 −2.21 −8.55−20.11 −44.67 −59.85 11c 0 −76.73 −63.09 −75.11 −83.26 −83.96 60.76 5−59.60 −71.20 −78.08 −87.61 −89.63 57.15 10 −74.36 −86.90 −85.03 −89.88−94.03 −35.94 20 −67.21 −74.90 −76.38 −87.01 −86.18 −52.70

Example 4—Non-Limiting Embodiments Exhibiting Improved AcousticConsistency

For sample assembly 25 and comparative sample assembly 13c, 5 samplesare made and tested for transmission loss and phase angle. Thevariability between parts is evaluated by the standard deviation oftransmission loss between samples at each of frequencies (500 Hz, 1,000Hz, 2,000 Hz, 5,000 Hz, 10,000 Hz, and 20,000 Hz). The mean transmissionloss and phase angle among the 5 samples are tabulated in Table 19 andTable 20. The standard deviation of transmission loss is tabulated inTable 21 and shown in FIG. 32. The raw transmission loss and phase angleis shown in FIG. 31, and the error bars in these figures are thedistribution of the measured values. As shown the sample assembliesexhibited a lower standard deviation than the comparative sampleassemblies, indicating that the sample assemblies provided betterconsistency from part to part.

TABLE 19 Transmission loss of sample assemblies and comparative sampleassemblies Transmission Loss (dB) Example Assembly # 500 Hz 1,000 Hz2,000 Hz 5,000 Hz 10,000 Hz 20,000 Hz 4a 25 25.90 26.80 26.90 26.7026.90 27.20 13c 19.494 14.3307 10.87 4.33 2.0955 4.7469

TABLE 20 Phase of sample assemblies and comparative sample assembliesPhase (degrees) Example Assembly # 500 Hz 1,000 Hz 2,000 Hz 5,000 Hz10,000 Hz 20,000 Hz 4a 25 1.16 1.99 1.13 −2.62 −7.19 −14.31 13c −44.64−64.00 −75.08 −83.62 −86.59 81.72

TABLE 21 Standard deviation of transmission loss of sample assemblies (n= 5) and comparative sample assemblies (n = 5) Standard Deviation ofTransmission Loss (dB) Example Assembly # 500 Hz 1,000 Hz 2,000 Hz 5,000Hz 10,000 Hz 20,000 Hz 4a 25 1.05 0.92 0.82 0.76 0.67 0.61 13c 3.63 3.113.65 2.40 1.38 1.48

Example 5: Tunable Transmission Loss

For a given membrane, the transmission loss can be tuned via the supportlayer. You can use a support layer with a higher airflow to reduce TLand vice versa.

TABLE 22 Transmission loss of sample assemblies Transmission Loss (dB)Example Assembly # 500 Hz 1,000 Hz 2,000 Hz 5,000 Hz 10,000 Hz 20,000 Hz5a 12 41.31 41.38 41.25 40.98 41.27 40.44 13 49.18 50.27 49.90 49.2750.02 48.81

TABLE 23 Phase of sample assemblies Phase (degrees) Assembly 500 1,0002,000 5,000 10,000 20,000 Example # Hz Hz Hz Hz Hz Hz 5a 12 1.82 0.751.60 1.38 0.40 1.40 13 3.33 2.18 −0.20 0.87 1.59 3.52While several embodiments of the present disclosure have been described,these embodiments are illustrative only, and not restrictive, and thatmany modifications may become apparent to those of ordinary skill in theart. For example, all dimensions discussed herein are provided asexamples only, and are intended to be illustrative and not restrictive.

The invention claimed is:
 1. An assembly comprising: a polymer membranehaving an air flow resistance ranging from 75 to 50,000 Rayls; and atleast one support layer; wherein at least a portion of the at least onesupport layer is in contact with the polymer membrane, wherein the atleast one support layer has an airflow resistance of from 10 to 5000Rayls; wherein the assembly has an effective stiffness that ranges from0.0002 Pa/nm to 3,000 Pa/nm when measured using the VibrationalDisplacement Test (“VDT”); and wherein the assembly has an acousticimpedance with a phase angle of +45 degrees to −45 degrees over afrequency range of 50 to 20,000 Hz as measured by the Impedance TubeTransfer Matrix Test (“ITTMT”).
 2. An assembly comprising: a polymermembrane having an air flow resistance ranging from 75 Rayls to 50,000Rayls; at least one support layer; wherein at least a portion of the atleast one support layer is in contact with the at least one polymermembrane, wherein the at least one support layer has an airflowresistance ranging from 10 Rayls to 5000 Rayls; and wherein the at leastone support layer has an effective stiffness that: ranges from 0.05Pa/nm to 25 Pa/nm measured using the Vibrational Displacement Test(“VDT”); and wherein the assembly has an acoustic impedance with a phaseangle of +45 degrees to −45 degrees over a frequency range of 50 to20,000 Hz as measured by the Impedance Tube Transfer Matrix Test(“ITTMT”).
 3. An assembly comprising: an airflow resistance of from 100to 50,000 Rayls; an effective stiffness from 0.0002 Pa/nm to 3,000 Pa/nmwhen measured using the Vibrational Displacement Test (“VDT”); and anacoustic impedance with a phase angle of +45 degrees to −45 degrees overa frequency range of 50 to 20,000 Hz as measured by the Impedance TubeTransfer Matrix Test (“ITTMT”).
 4. The assembly of claim 1, wherein theassembly has a water entry pressure ranging from 10 psi to 350 psi(“WEP”) measured in accordance with the Capillary Piston Test (“CPT”).5. The assembly of claim 1, wherein the assembly exhibits a transmissionloss of from 3 dB to 48 dB when measured by the Impedance Tube TransferMatrix Test (“ITTMT”) over the frequency range of 50 to 20,000 Hz.
 6. Anassembly comprising: an airflow resistance of from 100 to 50,000 Rayls;an effective stiffness from 0.0002 Pa/nm to 3,000 Pa/nm when measuredusing the Vibrational Displacement Test (“VDT”); and a transmission lossthat does not vary by more than 1.5 dB/octave over the frequency rangeof 50 to 20,000 Hz when measured by the Impedance Tube Transfer MatrixTest (“ITTMT”).
 7. The assembly of claim 1, wherein the polymer membranehas a thickness ranging from 0.025 microns to 300 microns.
 8. Theassembly of claim 1, wherein the polymer membrane comprises a pluralityof pores with different pore sizes.
 9. The assembly of claim 1, whereinthe plurality of pores has a maximum pore size ranging from 0.1 to 30microns.
 10. The assembly of claim 1, wherein the polymer membrane has abubble point ranging from 0.4 psi to 120 psi.
 11. The assembly of claim1, wherein the at least one support layer comprises a plurality ofopenings.
 12. The assembly of claim 1, wherein the largest dimension ofa single opening of the plurality of openings is 1 to 500 microns. 13.The assembly of claim 1, wherein the at least one support layer has athickness of 10 to 1000 microns.
 14. The assembly of claim 1, whereinthe at least one support layer has an effective open area of from 5% to98%.
 15. The assembly of claim 1, wherein the polymer membrane comprisesexpanded polytetrafluoroethylene (ePTFE).
 16. The assembly of claim 1,wherein the polymer membrane has a Young's Modulus ranging from 1 MPa to1000 MPa.
 17. The assembly of claim 1, wherein the assembly comprises asingle support layer.
 18. The assembly of claim 1, wherein the assemblycomprises at least two support layers.
 19. The assembly of claim 18,wherein the assembly comprises a first support layer and a secondsupport layer, and wherein the polymer membrane is sandwiched betweenthe first support layer the second support layer.
 20. The assembly ofclaim 18, wherein the first and second support layers comprise the samematerial.
 21. The assembly of claim 18, wherein the first and secondsupport layers comprise a different material.
 22. The assembly of claim1, comprising an adhesive between the polymer membrane and the at leastone support layer.
 23. The assembly of claim 1, wherein the at least onesupport layer comprises fiberglass.
 24. The assembly of claim 1, whereinthe at least one support layer comprises a metal.
 25. The assembly ofclaim 24, wherein the metal is brass.
 26. The assembly of claim 1,wherein the one or more support layers comprises a mesh.
 27. Theassembly of claim 26, wherein the mesh is woven polyethyleneterephthalate (PET) mesh.
 28. The assembly of claim 26, wherein the meshis extruded plastic non-woven mesh.